Volume 2,Issue 2,2006 Table of Contents
2006, 2(2).
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2006, 2(2).
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2006, 2(2):83-85.
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For LTPS AM-OLED displays, the spatial variation in the electrical characteristics of polysilicon TFTs will cause non-uniform pixel brightness and poor grayscale accuracy. The technological solution for this problem will open up the larger size application of LTPS AM-OLED displays. In this paper, a digital driver employing a FPGA device is designed to serve 2-inch color LTPS AM-OLED displays with 128× (160×3) resolution. A digital method of simultaneous address-display (SAD) and the digital visual interface (DVI) are introduced in the driving scheme. 100% display per, ratio can be obtained. Moving image with 16 grayscales is realized and has good image uniformity. This work is supported by the National ’863’ High Technology Research and Development Program of China. (2004AA303570)
For LTPS AM-OLED displays, the spatial variation in the electrical characteristics of polysilicon TFTs will cause non-uniform pixel brightness and poor grayscale accuracy. The technological solution for this problem will open up the larger size application of LTPS AM-OLED displays. In this paper, a digital driver employing a FPGA device is designed to serve 2-inch color LTPS AM-OLED displays with 128× (160×3) resolution. A digital method of simultaneous address-display (SAD) and the digital visual interface (DVI) are introduced in the driving scheme. 100% display per, ratio can be obtained. Moving image with 16 grayscales is realized and has good image uniformity. This work is supported by the National ’863’ High Technology Research and Development Program of China. (2004AA303570)
2006, 2(2):86-90.
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To improve the light-extraction-efficiency of OLED, we introduced PCS (Photonic Crystal Slab) structures into the interface of ITO layer and glass substrate. PCS structures with Taper unit cells are proved to be effective in reducing the energy of guided wave trapped in high refractive index material, and an increase of light-extraction-efficiency to 95.26% is gained. This enhancement is much greater than the traditional PCS with cylinder unit cells (60%–70%). Physical mechanisms of light-extraction-efficiency enhancement in these structures are further discussed. This work was supported by 2005 Nano-science Program of Shanghai Science Committee: study of sub-wavelength optical device with nanometer structure (0452NM056).
To improve the light-extraction-efficiency of OLED, we introduced PCS (Photonic Crystal Slab) structures into the interface of ITO layer and glass substrate. PCS structures with Taper unit cells are proved to be effective in reducing the energy of guided wave trapped in high refractive index material, and an increase of light-extraction-efficiency to 95.26% is gained. This enhancement is much greater than the traditional PCS with cylinder unit cells (60%–70%). Physical mechanisms of light-extraction-efficiency enhancement in these structures are further discussed. This work was supported by 2005 Nano-science Program of Shanghai Science Committee: study of sub-wavelength optical device with nanometer structure (0452NM056).
2006, 2(2):91-94.
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For the incomplete theory of the array confocal system,the more accurate theoretical model is built, and the new type of three-zone amplitude pupil filter is presented to improve the 3D detecting ability of the array confocal system. The 3D imaging equation based on Kirchhoffs diffraction theo. ry in the paper is more accurate, compared with the exciting theory, and it can describe the system imaging process more exactly. Using the evaluation criterion of 3D superresolution, the parameter of the filter pupil is optimized. It can reduce the axial and transversal FWHM of every detecting channel. The results of computer simulation and experiment prove that the filter can improve the axial and transversal resolution at the same time,which can increase the 3D measure capability.
For the incomplete theory of the array confocal system,the more accurate theoretical model is built, and the new type of three-zone amplitude pupil filter is presented to improve the 3D detecting ability of the array confocal system. The 3D imaging equation based on Kirchhoffs diffraction theo. ry in the paper is more accurate, compared with the exciting theory, and it can describe the system imaging process more exactly. Using the evaluation criterion of 3D superresolution, the parameter of the filter pupil is optimized. It can reduce the axial and transversal FWHM of every detecting channel. The results of computer simulation and experiment prove that the filter can improve the axial and transversal resolution at the same time,which can increase the 3D measure capability.
2006, 2(2):95-97.
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Based on the principle of FBG sensing mechanism, an alternating current sensor system, which uses a FBG attached on a magnetostrictive rod as the probe,was developed. A dynamic interrogation method was proposed based on wide band light source, by making use of the linear relationship between its power intensity and wavelength as spectrum filter. A 50 Hz AC signal is interrogated successfully through the developed system and the system transfer function was established. The amplitude and fre- quency of the AC signal to be measured can be well deduced through the transfer function of the system, so the alternating current measurement is accomplished.
Based on the principle of FBG sensing mechanism, an alternating current sensor system, which uses a FBG attached on a magnetostrictive rod as the probe,was developed. A dynamic interrogation method was proposed based on wide band light source, by making use of the linear relationship between its power intensity and wavelength as spectrum filter. A 50 Hz AC signal is interrogated successfully through the developed system and the system transfer function was established. The amplitude and fre- quency of the AC signal to be measured can be well deduced through the transfer function of the system, so the alternating current measurement is accomplished.
2006, 2(2):98-101.
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A design of coating on the entrance surface of the beam splitters with a transparent thin film of certain refractive index and thickness was presented. For this kind of beam splitters, it was possible to realize polarization-independent beam-splitting for chosen wavelength λ with incident angle ϕ. In addition, the simulation results using the coating designable software (Auto film) were consistent with the theoretical results, and the beam splitters are not sensitive to the small errors of film-thickness and film refractive-index over a broad spectra.
A design of coating on the entrance surface of the beam splitters with a transparent thin film of certain refractive index and thickness was presented. For this kind of beam splitters, it was possible to realize polarization-independent beam-splitting for chosen wavelength λ with incident angle ϕ. In addition, the simulation results using the coating designable software (Auto film) were consistent with the theoretical results, and the beam splitters are not sensitive to the small errors of film-thickness and film refractive-index over a broad spectra.
2006, 2(2):101-103.
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We report a method for improving temporal response of FBG-based temperature sensors. It has been demonstrated that by filling thermal conductive pastes between a sensing FBG and its package, the temporal response of the FBG-based temperature sensor can be significantly improved while isolating the strain and vibration.
We report a method for improving temporal response of FBG-based temperature sensors. It has been demonstrated that by filling thermal conductive pastes between a sensing FBG and its package, the temporal response of the FBG-based temperature sensor can be significantly improved while isolating the strain and vibration.
2006, 2(2):104-106.
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The phase information of an extended source is reconstructed by use of a two-zone (annular) phase-only filter in a coherent confocal scanning optical microscope. The dependence of its resolution on its source size is investigated theoretically by its three-dimensional optical transfer function (3D OTF). The results show that the resolution is improved, even though the source size is enlarged.
The phase information of an extended source is reconstructed by use of a two-zone (annular) phase-only filter in a coherent confocal scanning optical microscope. The dependence of its resolution on its source size is investigated theoretically by its three-dimensional optical transfer function (3D OTF). The results show that the resolution is improved, even though the source size is enlarged.
2006, 2(2):107-108.
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A bit-panel-plus-weight method has been proposed to realize gray-scale control of synchronous VGA display by passive matrix OLED. The presented VGA controller has been fabricated by FPGAs and can achieve a better result of gray-scale control by a 96*64 PMOLED panel.
A bit-panel-plus-weight method has been proposed to realize gray-scale control of synchronous VGA display by passive matrix OLED. The presented VGA controller has been fabricated by FPGAs and can achieve a better result of gray-scale control by a 96*64 PMOLED panel.
2006, 2(2):109-111.
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There are two peaks of different polarizations in the reflection spectrum of the side-hole fiber grating and their separation interval has a linear variation along with the pressure changing while it is insensitive to the temperature. We have proposed a novel measurement scheme based on polarization detection. The detection of peak separation is achieved by measuring the two peaks center wavelengths separately with all polarization maintaining fiber system. The side-hole fiber grating pressure sensing within, the range of 0∼3.5 MPa is realized successfully with the new scheme.
There are two peaks of different polarizations in the reflection spectrum of the side-hole fiber grating and their separation interval has a linear variation along with the pressure changing while it is insensitive to the temperature. We have proposed a novel measurement scheme based on polarization detection. The detection of peak separation is achieved by measuring the two peaks center wavelengths separately with all polarization maintaining fiber system. The side-hole fiber grating pressure sensing within, the range of 0∼3.5 MPa is realized successfully with the new scheme.
2006, 2(2):112-114.
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Second harmonic generation (SHG) of a new organic optical crystal-urea L-malic acid (ULMA) was studied. A comparison of SHG efficiency of ULMA and KDP at a fundamental wavelength of 1064 nm using the Kurtz powder method demonstrated that the second order nonlinear coefficient of ULMA is 1.57 times of that of KDP, and the damage threshold of ULMA is relatively higher. Finally, both Type I and Type II phase match angles of the biaxial crystal ULMA were calculated. Supported by the National Natural Science Foundation of China for Distinguished Young Scholars (Grant No. 60125513) and the Nature Science Foundation of Jiangsu province (Grant No. BK2004123)
Second harmonic generation (SHG) of a new organic optical crystal-urea L-malic acid (ULMA) was studied. A comparison of SHG efficiency of ULMA and KDP at a fundamental wavelength of 1064 nm using the Kurtz powder method demonstrated that the second order nonlinear coefficient of ULMA is 1.57 times of that of KDP, and the damage threshold of ULMA is relatively higher. Finally, both Type I and Type II phase match angles of the biaxial crystal ULMA were calculated. Supported by the National Natural Science Foundation of China for Distinguished Young Scholars (Grant No. 60125513) and the Nature Science Foundation of Jiangsu province (Grant No. BK2004123)
2006, 2(2):115-117.
Abstract:
7-hydroxyquinoline (7-HQ) is a kind of organic molecule with excited state proton transfer (ESPT) effect, and can be used as the material for all optical switching. This optical switching takes place via the ESPT effect depending on its intermolecular hydrogen bond formed with the solvent, and can have the effect of all optical switching. 7-HQ can not form intermolecular hydrogen bond with dimethyl sulfoxide (DMSO), so 7-HQ in DMSO solution cannot display the ESPT effect. However, after the solution was radiated by an UV laser, we found that 7-HQ could have ESPT effect. This phenomenon is reported and the mechanism is investigated for the first time in this paper. Supported by National Natural Science Foundation of China (No. 60178025) and the Foundation of Optoelectronic Information and Technology Laboratory, EMC.
7-hydroxyquinoline (7-HQ) is a kind of organic molecule with excited state proton transfer (ESPT) effect, and can be used as the material for all optical switching. This optical switching takes place via the ESPT effect depending on its intermolecular hydrogen bond formed with the solvent, and can have the effect of all optical switching. 7-HQ can not form intermolecular hydrogen bond with dimethyl sulfoxide (DMSO), so 7-HQ in DMSO solution cannot display the ESPT effect. However, after the solution was radiated by an UV laser, we found that 7-HQ could have ESPT effect. This phenomenon is reported and the mechanism is investigated for the first time in this paper. Supported by National Natural Science Foundation of China (No. 60178025) and the Foundation of Optoelectronic Information and Technology Laboratory, EMC.
2006, 2(2):118-121.
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The transmission property of the photonic crystal containing negative index material is analyzed by means of transfer matrix method. It is demonstrated that a defect mode appears in the conventional Bragg gap and the defect mode is sensitive to the position of the defect cell. For the first time to our knowledge we introduce two defects into such a structure and discuss the dependence of the transmission on the interval of the two defect cells. It is found that a wide degenerate defect mode appears in the Bragg gap,and this degenerate defect mode splits into two different defect modes when the two defect cells become closer.
The transmission property of the photonic crystal containing negative index material is analyzed by means of transfer matrix method. It is demonstrated that a defect mode appears in the conventional Bragg gap and the defect mode is sensitive to the position of the defect cell. For the first time to our knowledge we introduce two defects into such a structure and discuss the dependence of the transmission on the interval of the two defect cells. It is found that a wide degenerate defect mode appears in the Bragg gap,and this degenerate defect mode splits into two different defect modes when the two defect cells become closer.
2006, 2(2):122-124.
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The optical time division switch scheme using optical scanning was proposed in this paper. Quick switching can be realized by the optical element and optical system based on the proposed scheme. The modulation velocity of the proposed scheme can be of the order of nanosecond, which is quick enough for the next generation of optical communication. This scheme will be a key technology in the optical network. The principle of the scheme is studied. The structure of the scheme is proposed and the performance is analyzed.
The optical time division switch scheme using optical scanning was proposed in this paper. Quick switching can be realized by the optical element and optical system based on the proposed scheme. The modulation velocity of the proposed scheme can be of the order of nanosecond, which is quick enough for the next generation of optical communication. This scheme will be a key technology in the optical network. The principle of the scheme is studied. The structure of the scheme is proposed and the performance is analyzed.
2006, 2(2):125-129.
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A nonlinear optical loop mirror constructed from step-decreasing-dispersion fiber instead of DDF is used to compress optical pulse. Numerical simulations show that the effect of the proposed method is close to that of the method based on DDF. It not only resolves the difficulty of the making of DDF but also makes the design of the system more convenient.
A nonlinear optical loop mirror constructed from step-decreasing-dispersion fiber instead of DDF is used to compress optical pulse. Numerical simulations show that the effect of the proposed method is close to that of the method based on DDF. It not only resolves the difficulty of the making of DDF but also makes the design of the system more convenient.
2006, 2(2):130-132.
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Reasonable and effective buffer structures are proposed in core routers/nodes of optical burst switching. Based on the model of burst traffics and their contentions,the basic qualifications for the design of buffer structures are concluded. With these qualifications, buffer and switch integrated structures are proposed; and by conclusion and expansion,the classification rules of buffer structures are also proposed from different angles. The schemes to integrate structures are analyzed and simulated.
Reasonable and effective buffer structures are proposed in core routers/nodes of optical burst switching. Based on the model of burst traffics and their contentions,the basic qualifications for the design of buffer structures are concluded. With these qualifications, buffer and switch integrated structures are proposed; and by conclusion and expansion,the classification rules of buffer structures are also proposed from different angles. The schemes to integrate structures are analyzed and simulated.
2006, 2(2):133-135.
Abstract:
In wireless optical communication, effects of scintillation make average Bit Error Rate (BER) deteriorate. To improve system performance, PCCC (Parallel Concatenated Convolutional Code) encoding scheme is employed, and upper bound on the bit error rate is given by considering the effects of scintillation, APD noise and thermal noise. Simulation results show that the PCCC encoding scheme can relieve turbulence-induced intensity fluctuations and the system performance is improved remarkably. Founded by National 863 project (NO: 2002AA107496), Youth Foundation Project of UESTC(NO: JX03018)
In wireless optical communication, effects of scintillation make average Bit Error Rate (BER) deteriorate. To improve system performance, PCCC (Parallel Concatenated Convolutional Code) encoding scheme is employed, and upper bound on the bit error rate is given by considering the effects of scintillation, APD noise and thermal noise. Simulation results show that the PCCC encoding scheme can relieve turbulence-induced intensity fluctuations and the system performance is improved remarkably. Founded by National 863 project (NO: 2002AA107496), Youth Foundation Project of UESTC(NO: JX03018)
2006, 2(2):136-138.
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A new approach to extract phase feature of 3-D objects based on wavelength-scanning digital holography and numerical reconstruction technique is proposed in this paper. A number of holograms are recorded on a digital camera and reconstructed numerically by a computer with different wavelengths spaced at regular intervals. The theoretical analysis and computer simulations demonstrate that those pixels with the same phase of a 3-D object can focus on the same reconstruction plane. And those pixels with different phase of a 3-D object focus on the different reconstruction planes. Therefore the phase information of a 3-D object can be described by a series of reconstructed images on different planes.
A new approach to extract phase feature of 3-D objects based on wavelength-scanning digital holography and numerical reconstruction technique is proposed in this paper. A number of holograms are recorded on a digital camera and reconstructed numerically by a computer with different wavelengths spaced at regular intervals. The theoretical analysis and computer simulations demonstrate that those pixels with the same phase of a 3-D object can focus on the same reconstruction plane. And those pixels with different phase of a 3-D object focus on the different reconstruction planes. Therefore the phase information of a 3-D object can be described by a series of reconstructed images on different planes.
2006, 2(2):139-141.
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In this letter a fiber Bragg grating (FBG) interrogation system based on thermistance and matching-FBG of temperature sensitivity enhancement is proposed and demonstrated. According to the relationship between the center wavelength of the matching-FBG and the resistance value of the thermistance, the scheme interrogates the wavelength-shift by adjusting the matching-FBGs temperature and detecting the resistance value of the thermistance. In measure experiments, the results show that the precision of the proposed system is 0.048 nm in a range of 9.4 nm. This work was supported by the Natural Science Foundation of Beijing (Serial Number is: 030313) and the National Natural Science Foundation of China (Serial Number is: 60372100).
In this letter a fiber Bragg grating (FBG) interrogation system based on thermistance and matching-FBG of temperature sensitivity enhancement is proposed and demonstrated. According to the relationship between the center wavelength of the matching-FBG and the resistance value of the thermistance, the scheme interrogates the wavelength-shift by adjusting the matching-FBGs temperature and detecting the resistance value of the thermistance. In measure experiments, the results show that the precision of the proposed system is 0.048 nm in a range of 9.4 nm. This work was supported by the Natural Science Foundation of Beijing (Serial Number is: 030313) and the National Natural Science Foundation of China (Serial Number is: 60372100).
2006, 2(2):142-144.
Abstract:
Semiconductor optical amplifiers (SOA) are optical amplifying devices and key parts in optical switches and optical buffers. They are largely used in communication system. Linewidth enhancement factor is an important parameter for SOA. A method is proposed to measure the linewidth enhancement factor with Sagnac interferometer. Cross phase modulation (XPM) and cross gain modulation (XGM) coexist in SOA. The quantitative relation of linewidth enhancement factor to XGM and the interference extinction ratio is given. The experimental results indicate that the value of linewidth enhancement factor changes from 5. 13 to 6. 24 when the electric current varies from 130 mA to 240 mA. Supported by the National Natural Science Foundation of China (Grant No. 60272010) and National 863 project (NO. 2002AA122510)
Semiconductor optical amplifiers (SOA) are optical amplifying devices and key parts in optical switches and optical buffers. They are largely used in communication system. Linewidth enhancement factor is an important parameter for SOA. A method is proposed to measure the linewidth enhancement factor with Sagnac interferometer. Cross phase modulation (XPM) and cross gain modulation (XGM) coexist in SOA. The quantitative relation of linewidth enhancement factor to XGM and the interference extinction ratio is given. The experimental results indicate that the value of linewidth enhancement factor changes from 5. 13 to 6. 24 when the electric current varies from 130 mA to 240 mA. Supported by the National Natural Science Foundation of China (Grant No. 60272010) and National 863 project (NO. 2002AA122510)
2006, 2(2):145-147.
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A real-time prototype of drowsy driver monitoring system using infrared sources to detect and track the eyes is presented. A special hardware is designed for controlling the LEDs and real-time image acquisition. This method adopts the differential image to enhance the accuracy and robustness of eye detection. A Kalman filter is implemented to track the eyes. The experimental results are discussed. The system is non-invesive, fast and reasonably accurate.
A real-time prototype of drowsy driver monitoring system using infrared sources to detect and track the eyes is presented. A special hardware is designed for controlling the LEDs and real-time image acquisition. This method adopts the differential image to enhance the accuracy and robustness of eye detection. A Kalman filter is implemented to track the eyes. The experimental results are discussed. The system is non-invesive, fast and reasonably accurate.
2006, 2(2):148-150.
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An algorithm is suggested to compensate the inside fringe in reconstruction field for the iterative distortion when an opaque object exists. With numerical simulation, a model field with an opaque object is reconstructed by a new algebraic reconstructing technique (ART), named Simple Self-correlative ART (SSART), which shows that the inside fringe of the reconstructed field is quite irregular with serious profile distortion. An algorithm of the compensation of the inside fringe for the iterative distortion is suggested and applied to the reconstruction of the field. It is found that the reconstructed field is quite similar to the model. With the compensation algorithm, the field with an opaque object in can be accurately reconstructed by SSART. This project was supported by China Postdoctoral Science Foundation (2004036121), the National Natural Science Foundation of China (10404022) and education bureau of Shandong province (J04A63)
An algorithm is suggested to compensate the inside fringe in reconstruction field for the iterative distortion when an opaque object exists. With numerical simulation, a model field with an opaque object is reconstructed by a new algebraic reconstructing technique (ART), named Simple Self-correlative ART (SSART), which shows that the inside fringe of the reconstructed field is quite irregular with serious profile distortion. An algorithm of the compensation of the inside fringe for the iterative distortion is suggested and applied to the reconstruction of the field. It is found that the reconstructed field is quite similar to the model. With the compensation algorithm, the field with an opaque object in can be accurately reconstructed by SSART. This project was supported by China Postdoctoral Science Foundation (2004036121), the National Natural Science Foundation of China (10404022) and education bureau of Shandong province (J04A63)
2006, 2(2):151-154.
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An order morphology transform is presented to filter and segment which is done by different percentile. Filter Is done flexibly by different size structure element with several percent. The threshold which for normal segment way such as Ostu decides is more lower when a low SNR Image Is processing especially the foreground is small or dot. The foreground can not be identified effectively in those case. Adaptive multl-threshold segment Is defined by percent value of order morphology. Analysis and results indicate that this way is more adaptive to different SNR fluorescence images. It could be applied to process high-density chips.
An order morphology transform is presented to filter and segment which is done by different percentile. Filter Is done flexibly by different size structure element with several percent. The threshold which for normal segment way such as Ostu decides is more lower when a low SNR Image Is processing especially the foreground is small or dot. The foreground can not be identified effectively in those case. Adaptive multl-threshold segment Is defined by percent value of order morphology. Analysis and results indicate that this way is more adaptive to different SNR fluorescence images. It could be applied to process high-density chips.
2006, 2(2):155-157.
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The paper focuses on location of seal imprints on Chinese bank-checks based on region growing. Region growing method can be applied to searching and locating connection region in an image. A seal imprint,however, is generally composed of various connection regions which are unconnected to each other. In order to locate the seal imprint,these connection regions must be fused together. In the paper, an algorithm for locating seal imprints on Chinese bankchecks based on region growing is proposed, of which a fusion criterion for connection regions in a seal imprint is put forth based on the image feature of Chinese bankcheck,and a center-rays model is proposed to find the topological relationship between connection regions,for which externally-tangent rectangle of region is used as the mark of location of region. The location experiment is achieved with a false-acceptance rate of 7.1% and a false-rejection rate of 0 % on Chinese bankcheck.
The paper focuses on location of seal imprints on Chinese bank-checks based on region growing. Region growing method can be applied to searching and locating connection region in an image. A seal imprint,however, is generally composed of various connection regions which are unconnected to each other. In order to locate the seal imprint,these connection regions must be fused together. In the paper, an algorithm for locating seal imprints on Chinese bankchecks based on region growing is proposed, of which a fusion criterion for connection regions in a seal imprint is put forth based on the image feature of Chinese bankcheck,and a center-rays model is proposed to find the topological relationship between connection regions,for which externally-tangent rectangle of region is used as the mark of location of region. The location experiment is achieved with a false-acceptance rate of 7.1% and a false-rejection rate of 0 % on Chinese bankcheck.
2006, 2(2):158-162.
Abstract:
Charge recombination in reaction center (RC) of photosystem II(PS II) is regarded as the location of 685 nm delayed fluorescence (DF). The mechanism of 730 nm component appearing in the DF spectrum for chloroplast was studied by various spectral analysis methods. Experimental results of the DF spectrum at different chloroplast concentration show that the intensity of peaks at 685nm and 730 nm ascends with the chloroplast concentration increasing when the concentration is relatively low. When the concentration increases to the level of 7.8μg/ml, a maximum intensity of the peak at 685 nm appears but the intensity of 730 nm peak still increases. The peak at 730 nm finally reaches a maximum intensity at the chloroplast concentration of 31.2 μg/ml while the intensity of the 685 nm peak has apparently fallen down. The results of absorption spectrum show that the ratios of A685 to A730 keep almost constant with the increasing of chloroplast concentration. Furthermore, the excitation spectrum for 730 nm fluorescence shows that the 685nm light has high excitation efficiency. These results indicate that the 730 nm component of DF spectrum is the fluorescence of chlorophyll in PS I RC excited by 685 nm DF. Meanwhile, this can be further verified by the invariability of DF spectrum at different delay time (1 second∼9 seconds). This research is supported by the National Natural Science Foundation of China (60378043), and supported by the Opening Foundation of the Key Laboratory of Opto-Electronic Technology and Intelligent Control (Lanzhou Jiaotong University), Ministry of Education (K04108)
Charge recombination in reaction center (RC) of photosystem II(PS II) is regarded as the location of 685 nm delayed fluorescence (DF). The mechanism of 730 nm component appearing in the DF spectrum for chloroplast was studied by various spectral analysis methods. Experimental results of the DF spectrum at different chloroplast concentration show that the intensity of peaks at 685nm and 730 nm ascends with the chloroplast concentration increasing when the concentration is relatively low. When the concentration increases to the level of 7.8μg/ml, a maximum intensity of the peak at 685 nm appears but the intensity of 730 nm peak still increases. The peak at 730 nm finally reaches a maximum intensity at the chloroplast concentration of 31.2 μg/ml while the intensity of the 685 nm peak has apparently fallen down. The results of absorption spectrum show that the ratios of A685 to A730 keep almost constant with the increasing of chloroplast concentration. Furthermore, the excitation spectrum for 730 nm fluorescence shows that the 685nm light has high excitation efficiency. These results indicate that the 730 nm component of DF spectrum is the fluorescence of chlorophyll in PS I RC excited by 685 nm DF. Meanwhile, this can be further verified by the invariability of DF spectrum at different delay time (1 second∼9 seconds). This research is supported by the National Natural Science Foundation of China (60378043), and supported by the Opening Foundation of the Key Laboratory of Opto-Electronic Technology and Intelligent Control (Lanzhou Jiaotong University), Ministry of Education (K04108)
2006, 2(2):F0002-F0002,I0001.
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2006, 2(2):I0002-I0002.
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