CAJ | 학술논문

为避免传统激光外差探测中强本振信号带来的散粒噪声影响,着眼于光子级别的弱本振激光外差探测信噪比分析.首先,将脉冲体制弱本振激光外差探测信噪比表达式应用于分段连续弱本振激光外差探测中,获得中心频率为221 kHz外差信号的解析,且信噪比的理论计算和实验值吻合.其次,采用数据段细分功率谱累积技术,在相同的信噪比情况下,所利用的数据量总数降低为传统功率谱累积方法的1/10,提高了数据利用率,且在功率谱累积次数较少时,信噪改善比近似遵守 m 规律.
위피면전통격광외차탐측중강본진신호대래적산립조성영향,착안우광자급별적약본진격광외차탐측신조비분석.수선,장맥충체제약본진격광외차탐측신조비표체식응용우분단련속약본진격광외차탐측중,획득중심빈솔위221 kHz외차신호적해석,차신조비적이론계산화실험치문합.기차,채용수거단세분공솔보루적기술,재상동적신조비정황하,소이용적수거량총수강저위전통공솔보루적방법적1/10,제고료수거이용솔,차재공솔보루적차수교소시,신조개선비근사준수 m 규률.
In order to avoid the influence of shot noise due to the powerful local oscillator(LO) in traditional laser heterodyne detection, SNR (signal to noise ratio) analysis of laser heterodyne detection with a weak LO un?der photon-level is presented. Firstly, the expression of SNR with a pulsed laser is applied in the condition of par?tial CW(continuous wave) and weak LO laser heterodyne detection. The spectrum of the heterodyne signal with the center frequency 221 kHz has been achieved and the theoretical value of SNR is in agreement with that of the experiment. Secondly, the techniques of data segment fractionizing and PSD (Power Spectral Density) averaging are used in the research of SNR. The results showed that the volume of the data has been decreased to 0.1 times compared with the traditional PSD averaging, the data resource is fully used during signal processing and SNIR (Signal to Noise Improved Ratio) nearly obeys the m rule( m is the averaging time) under a small quantity of data segments.