optical coherent detection 中文意思是什麼
optical coherent detection
解釋
光相干檢測-
In order to improve the existing pr adaptive optical heterodyne detection system ( praohds ), a new praohds is proposed based on sppc and mppc coexistence. the experimental study of the system is completed by equal amplitude ar + laser beams, poorly coherent equal amplitude solid - state laser beams and high speed amplitude - modulated solid - state laser beams through distorting media. experimental results indicate that the new system is applicable
為了改進現有的光折變自適應光外差探測系統（ praohds ） ，本文利用sppc和mppc同時共存的特性，提出了一種新型的praohds ，並利用ar ~ +等幅激光、相干性較差的固體等幅激光以及固體高速振幅調制激光對新系統進行了畸變光束的自適應光外差探測實驗研究，結果證明了新系統在實際應用中的可行性。 -
A coherent electromagnetic pulse in the range between the far - infrared and microwave region is used as a detection source. the amplitude of the wave is recorded by electro - optical or photoconductive sampling. after fast fourier transform, the amplitude and phase of the wave is given, then the complex refractive index standing for the absorption and dispersion of the material in thz region is extracted
Thz （ 10 ~ （ 12 ） hz ）時域光譜技術是20世紀90年代發展起來的一種新型的光譜測量技術，它使用頻率介於遠紅外和微波之間的相干電磁輻射脈沖作為探測源，利用電光取樣或光電導取樣的方法直接記錄thz輻射電場的振幅時間波形，通過傅立葉變換得到測量信號振幅和相位的光譜分佈，進而獲得材料在thz波段的復介電常數，即色散及吸收等信息。 -
Two wedge interferometers are designed that the thickness of one is higher than the other. so when the incident coherent light through the interferometers can acquire two fringe patterns which having space shift, but the incident incoherent light only result in consistent intensity signal. through a differentiating amplifier, two signals subtract which can eliminate noise of background and result in higher contrast ratio fringe signals. this method largely improves the system and the ability of detection. the spacing of line fringes is a function of incident laser wavelength, by analyzing, we can extract the wavelength of incident laser. the optical unit analyzing and results also simulated with matlab
當背景光入射時，直接穿過干涉儀，僅發生強度的衰減，在兩個探測平面上產生幅度基本一致的灰度信號，通過差分放大器，相消為零，從而抑制了背景干擾。當激光信號入射，穿過干涉儀時受到調制，在探測平面上產生干涉條紋。通過所設計的存在平均厚度差的雙楔形干涉儀，兩路干涉條紋圖案出現相對移位：在兩個探測平面對應的位置上，一路出現亮紋，另一路出現暗紋。
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