Contents
1982
Volume: 2 Issue 5
17 Article(s)
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Research Article
Fourier Optics and Signal Processing
Enhancement of S/N of spectrograms with an astigmatic system
WANG ZHIJIANG, WANG NENGHE, LI QINGXUN, and WU MINGZHEN
The imaging property of an astigmatic system is analysed in the matrix form. On the x-direotion spectrogram is conjugated vdth the image place. But on the y-direction the source place is conjugated with the image place. In this way the astigmatio system plays a role to average the noise on the y-direction. The source oThe imaging property of an astigmatic system is analysed in the matrix form. On the x-direotion spectrogram is conjugated vdth the image place. But on the y-direction the source place is conjugated with the image place. In this way the astigmatio system plays a role to average the noise on the y-direction. The source of noise of the laser plasma X-ray spectrogram are quantum noise of X-ray and granularity of the plate. The former is multiplicative to signal, but tho rear is added. The two types of the noise may bo averaged with an astigmatic system. Experimental results are represented..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 2, Issue 5, 400 (1982)
Some application of spatial modulation to optical information processing
ZHANG CHENGHUA
After applying spatial modulation to holographio translation, the SNR of the on-tpui is improved, and ihe translation capacity is increased greatly. The experiments presented in this paper demonstrate that a hologram can translate four telegraphic codes into Chinese characters，and two translating channels (Chinese / EnAfter applying spatial modulation to holographio translation, the SNR of the on-tpui is improved, and ihe translation capacity is increased greatly. The experiments presented in this paper demonstrate that a hologram can translate four telegraphic codes into Chinese characters，and two translating channels (Chinese / English and Chinese/ Russian) can be recorded on one holographic plate. With the frequency and orientation of modulating grating being altered, it is possible for a hologram to translate more than a hundred words. In those oases the characters may be 61—modulated beforehand, a character (such as 0) can be recognized distinotily without being confused with another very resemble one (Q), and it is possible to realize multi-reoognition. A modulating grating can replace a random phase shifter for holographic information storage. A low frequency phase grating does not reduce the resolution of retrieval page obviously. A halftone picture may be regarded as a group of width-modulated spatial pulses, therefore it can be holographically storage*! directly without the concentration of intensity on the Fourier transform plane, by u^ing 汐一modulation，multi-storage is organized on the spatial frequency piano, the experimental results show that the cross talk is very low..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 2, Issue 5, 406 (1982)
Instrumentation, Measurement and Metrology
The theoretical analysis and experimental results on the self-calibration technique of silicon pholodiode
LI TONGBAO
The several factors on which the outer quantum efficiency of the silicon photodiodes depend upon, especially the collection efficiency of the devices have been discussed. The universal formula and simplified formula for determining "the quan-tum feffioienoy of the devices have also been shown. For three silicon phThe several factors on which the outer quantum efficiency of the silicon photodiodes depend upon, especially the collection efficiency of the devices have been discussed. The universal formula and simplified formula for determining "the quan-tum feffioienoy of the devices have also been shown. For three silicon phoiodiodes on which ihe self-calibration have been done we obtained ihai -the unoeriainij of determining outer quantum efficiency was about ±0.05%, ihe consistency of measuring laser beam power was abou-t ±0.05% also, and finally the agreement with the results from the absolute radiometers was better than ±0.2%..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 2, Issue 5, 452 (1982)
Lasers and Laser Optics
Research on photodissociation of mercury halides with excimer laser
SHANGGUAN CHENG, YUAN CAILAI, and YE CHAO
Intense super radiation at 404.7 nm (73S1 ~ 63P0), 435.8 nm (73S1 ~ 63P1) and 546.1 nm (73S1~ 63P2)from atomic Hg produced by photodissociation of HgBr2 and HgI2 respectively with an ArF exoimer laser at 193nm and a KrCl excimer laser at 222nm has been observed. The mechanism of selected excitation of Hg(73S1) state isIntense super radiation at 404.7 nm (73S1 ~ 63P0), 435.8 nm (73S1 ~ 63P1) and 546.1 nm (73S1~ 63P2)from atomic Hg produced by photodissociation of HgBr2 and HgI2 respectively with an ArF exoimer laser at 193nm and a KrCl excimer laser at 222nm has been observed. The mechanism of selected excitation of Hg(73S1) state is discussed..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 2, Issue 5, 414 (1982)
A small-signal theory of free-electron laser amplifier
YIN YUANZHAO
The single-partiol? model is used to explain the working principle of free-eloofcroa laser amplifier. After linearizing the motion equation of electron,we got the small-signal gain. The results show that the electron beam has suitable initial velocity distribution, the initial phases of the static periodic magnetic fieThe single-partiol? model is used to explain the working principle of free-eloofcroa laser amplifier. After linearizing the motion equation of electron,we got the small-signal gain. The results show that the electron beam has suitable initial velocity distribution, the initial phases of the static periodic magnetic field and incidont oleotromagnetio wave have definite relation, the syohronization requirement between electrons and wave and the cyclotron rosonace oondition are satisfied. The electrons can transfer their energy to the wave efficiently and oonstanily so that laser amplitioation can be achievod..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 2, Issue 5, 420 (1982)
Maximum pumping power for high power CW Nd:YAG laser limited by thermal stresses
YE BIQING, and MA ZHONGLIN
The problems have been investigated concerning the output properties and accumulative life of a high power CW Nd:YAG laser with many hundreds watts output, and the rupture of Nd:YAG rod induced by high pumping power has been analysed.The problems have been investigated concerning the output properties and accumulative life of a high power CW Nd:YAG laser with many hundreds watts output, and the rupture of Nd:YAG rod induced by high pumping power has been analysed..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 2, Issue 5, 425 (1982)
Materials
The nonlinear optical properties of disodium sulfosaticylate
SU GENBO, LIAN TINGCHANG, LI ZHENGDONG, WANG WENCHENG, and WANG GONGMING
A new nonlinear optical crystal^ disodium sulfosaiicylaLe (DSB) is reported. Large single crystal with good optical quality have been grown in soluiion by the cooling method. X-ray structural determination shows that the crystal belongs to orthorhombio system with poini group mm 2. Its transmitted spectrum is in the raA new nonlinear optical crystal^ disodium sulfosaiicylaLe (DSB) is reported. Large single crystal with good optical quality have been grown in soluiion by the cooling method. X-ray structural determination shows that the crystal belongs to orthorhombio system with poini group mm 2. Its transmitted spectrum is in the range of 870~ 1300 nm. The refractive indices ai various wavelengths as well as the effeoiive nonlinear coefficients dm have been measured. Based on the oalculafcion of the phase-ma tching angles φι and φπ, the values of t/3i and. d32 of DSS crystal relative to of KDP crystal have been obtained. It is found, thai the SHG conversion efficiency of DSS crystal is about 3.5 times than ihai of KDP crystal. Moreover, the optical damage threshold is higher than 200 MW/om2. The crystal exhibits a somewhat better deliquescent resistant proper ty than the KDP crystal. is believed thai this crystal has some practical values of using as the SHG element for 1.06 μ laser..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 2, Issue 5, 439 (1982)
A study of F+2-centers generation in LiF crystals
WANG TINGJI, and ZHANG ZHISAN
The generation of F+2-centers in LiF crystals is studied. Experiments show that in order to acquire a better understanding of the physical processes involved, two parameters, dosage-rate r and irradiation-time t rather than a single one, dosage R should be used to specify the irradiation condition. The density in the oThe generation of F+2-centers in LiF crystals is studied. Experiments show that in order to acquire a better understanding of the physical processes involved, two parameters, dosage-rate r and irradiation-time t rather than a single one, dosage R should be used to specify the irradiation condition. The density in the order of 1016 F+2-centers per cubic centimeter is obtained in our experiments. The density of F+2-centers depends on both the radiation source and the quality of the crystals. An expression derived from the experiments for maximum density is given by Nmax = krT. In addition) judging from the residual fluorescence of F^-oen fcers in LiF crystals， it seems reasonable io assume that two states of F2-centers exist in LiF crystals. The life-iime of F^-centers is also measured..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 2, Issue 5, 445 (1982)
Optical Devices
Picosecond photography of laser irradiated thin foils
TENG YUNGLU, R. FEDOSEJEVS, R. SIGEL, K. EIDMANN, R. PETSOH, and G. SPINDLER
Thin plastic foils (2~10 μm thickness) were irradiated with the iodine laser ASTEEIX III (λ=1.3 μm) Pulse energy was 100 J, pulse duration 300 ps; the intensity on target was varied in the range 1014?5x 10炀 W.cm-2- An active-passive mode-locked,fJash -lamp-pumpad dye laser was synchronized with the iodine laser pulse. Thin plastic foils (2~10 μm thickness) were irradiated with the iodine laser ASTEEIX III (λ=1.3 μm) Pulse energy was 100 J, pulse duration 300 ps; the intensity on target was varied in the range 1014?5x 10炀 W.cm-2- An active-passive mode-locked,fJash -lamp-pumpad dye laser was synchronized with the iodine laser pulse. A siaglo dye ]asei pulse (?10 ps duration) was used to study the gasdynamic motion of the foil matexial during and aifter irradiation by shadowgraphy. Besides the expected acceleration of tZie foil under one-side irradiation we also find strong distuxbaneea of the foil at distances far from the irradiated area, especially at high irxadiances. The results will be discussed and compared with previous, calorimetric measurements of thin foil acceleration..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 2, Issue 5, 431 (1982)
Rapid Communications
The design and fabrication of wedge-ring detectors for optical power spectrum analysis
ZHAO HUANQING, DU YUANCHENG, ZHAO ZAIZHONG, and ZHANG ZHIMING
In hybrid optical power spectrum analysis systems, the wedge-ring array deteclor functions as an optical to electrical interface device for sampling the optical spatial frequency information for further processing by digit computer. The detector designed and fabricated in our laboratory consists of 32 semi-circular rinIn hybrid optical power spectrum analysis systems, the wedge-ring array deteclor functions as an optical to electrical interface device for sampling the optical spatial frequency information for further processing by digit computer. The detector designed and fabricated in our laboratory consists of 32 semi-circular rings for detecting the radial information and with 32 wedge-shaped sections for the directional information in the spectrum. The detector is made on a silicon wafer diameter is about 32 mm with carefully controlled diffusion process in order to obtain uniformity in response and sensitivity. The average responsibility is about 0.5mA/mW for "the wedges and annular rings of ihe corresponding areas, the time constant is about 150 μθ. The spatial bandwid-fch could be up io 100 cycles with an optical transform lens of 240 mm fooal length irradiaied by ihe He-Ne radiation of 632.8 nm..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 2, Issue 5, 458 (1982)
Electric properties of piezoelectric ceramic thin plate under action of ruby pulse laser radiation
ZHENG CHUANXIANG, ZHOU YEWEI, YANG SHOUZHI, and XIE JIAN
Under action of normal pulse ruby laser radiation, electric properties of a piezoelectric ceramic thin plate of PZT system have been studied in our experiments. We have observed an unusual phenomenon before a small hole having been drilled by focusing laser radiation on the sample. When the laser radiation directs on iUnder action of normal pulse ruby laser radiation, electric properties of a piezoelectric ceramic thin plate of PZT system have been studied in our experiments. We have observed an unusual phenomenon before a small hole having been drilled by focusing laser radiation on the sample. When the laser radiation directs on it in either polarizing field (positive) or opposite direction (negative), we observe electric signals between two surface electrodes having same shapes and amplitudes, and their polarity is constant. As soon as a small hole has been drilled on the samples, in both sides above illumination cases, we observe eleotrio signals having jump changes in different ways, and one of them may be changed in polarity. This paper reports obtained experiraental results in our work, and makes a primary discussion to them..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 2, Issue 5, 463 (1982)
The calculation of the optimum phase matching angle in SHG of LiCOOH.H2O
SONG CHANGLI, and WANG LUCHUAN
In this paper, the variation of the phase matching angle and the effective nonlinear coefficient versus the fundamental wavelength in a second harmonic generation of the lithium formate roonohydrate (LiCOOH ‘HaO)of the mm 2 type crystal are calculated. It is found that there is one (or two) optimum phase matching angleIn this paper, the variation of the phase matching angle and the effective nonlinear coefficient versus the fundamental wavelength in a second harmonic generation of the lithium formate roonohydrate (LiCOOH ‘HaO)of the mm 2 type crystal are calculated. It is found that there is one (or two) optimum phase matching angle {θ, φ) for each fundamental wave, at which the second harmonic conversion efficiency is highest. Fitted formula for the variation of the phase matching angle versus the fundamental wavelength is obtained.Second harmonic generation for 0.53μ, 0.35 μ and 0.266 μ are observed from the crystals cuied at the computative angle..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 2, Issue 5, 468 (1982)
The protective coatings on sodium chloride crystals
ZHANG BAOREN, and WU LIMING
It has been shown experimently thai the protective coatings of "F46" or "202" etc deposited on the surface of sodium chloride crystals by vacuum evaporation can endure continuous expansion of CO2 laser at 750 W/cm2,in addition to its merit of moisture proof effect.It has been shown experimently thai the protective coatings of "F46" or "202" etc deposited on the surface of sodium chloride crystals by vacuum evaporation can endure continuous expansion of CO2 laser at 750 W/cm2,in addition to its merit of moisture proof effect..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 2, Issue 5, 473 (1982)
Super-Gaussian photographic-plate apodizing aperture
ZHENG YUXIA, LIN ZUNQI, and YU WENYAN
In this paper, the results of super-Gaussian photographic plate aperture research are presented. The design and fabrication of this kind of apodizing aperture and it s results of practical application are reported.In this paper, the results of super-Gaussian photographic plate aperture research are presented. The design and fabrication of this kind of apodizing aperture and it s results of practical application are reported..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 2, Issue 5, 477 (1982)
Spectroscopy
Atomic velocity-changing collisions in polarization excitation spectroscopy (Ⅱ)
SHEN WEIDIAN, and WANG ZHAOYONG
Polarization intermodulated. excitation (POLINEX) spectroscopy is a new nonlinear high resolution speotroHCOpy. It combines polarization spectroscopy with intermodulated fluorescence spectroscopy. So the POLINEX spectroscopy has some advantages of them. In author's former paper, we had used the rate equation approaPolarization intermodulated. excitation (POLINEX) spectroscopy is a new nonlinear high resolution speotroHCOpy. It combines polarization spectroscopy with intermodulated fluorescence spectroscopy. So the POLINEX spectroscopy has some advantages of them. In author's former paper, we had used the rate equation approach to analyze how the Doppler background caused by atomic collisions was eliminated and how the Loren-tzian line shape was kept. In this paper, we use the semiolassioal theory of Lamb to analyze the POLINEX spectroscopy further more. This method is more reasonable. Considering laser beam's polarization^ energy level's degeneracy and collision cross relaxation, by means of the equation of motion of density matrix, we have calculated the polarizability of the atomic system submitted to laser beams and J2 to the third order χ(3). Then，from %m we have evaluated, nonlinear components of the absorption ooeffioient a. So we can obtain the strength and shape of the intermodulated signal in POLINEX spectroscopy. The conclusion is in conformity with the experimental results. Moreover, it predicts the pressure shift and pressure broadening which can't be predicted by the rate equation approaoh..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 2, Issue 5, 385 (1982)
Study on optical spectra of ions in phosphate, fluorophosphate and fluoride glasses I:Cr3+,Mo3+
LIU HUIMIN, CHEN SHUCHUN, and GAN FUXI
Absorption, fluorescence spectra and lifetime mesurements of Or3+ in the three kinds of glass bases have been performed, and the analysis and calculation of the speotral data based on the ligand field theory have been carried out. The results are consistent with, the experiments. Moreover, it is found that in order of Absorption, fluorescence spectra and lifetime mesurements of Or3+ in the three kinds of glass bases have been performed, and the analysis and calculation of the speotral data based on the ligand field theory have been carried out. The results are consistent with, the experiments. Moreover, it is found that in order of phosphate -> fluorophosphate —fluoride glasses the joiiic contribution of the chemical bond between the central activated ions and ligands increases gradually with, the increase of Racah Β parameters. Corresponding peak positions of absorption spectra and fluorescence spectra shift to shorter wavelength. Meanwhile, the experiments also show that the increase of fluorescence intensity and lifetime and. the weakening of temperature quenching effect of glassed from phosphate to fluorophosphate can be considered as the deoreage of non-radiation probability. In this paper, absorption and fluorescence spectra of Mo3+ in phosphate glass have also been studied,The ligand field strength DQ of Mo3+ is larger in comparison with that of Gr3+..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 2, Issue 5, 393 (1982)
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