Grating scanning type spectrograph of simplifying digital lock-in amplifier and detection method

• Main Authors: WANG ZHIHONG, LIU JIE, JI XUFEI, WANG JINGRU
• Format: Patent
• Language: English
• Published: 23.12.2015
• Subjects: COLORIMETRY; MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT,POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRA-RED,VISIBLE OR ULTRA-VIOLET LIGHT; MEASURING; PHYSICS; RADIATION PYROMETRY; TESTING

The present invention relates to a grating scanning type spectrograph of simplifying a digital lock-in amplifier and a detection method. The grating scanning type spectrograph of simplifying the digital lock-in amplifier is formed by connecting an upper computer, a detection control system, a voltage stabilization control circuit, a light source, a modulator and a monochromator with the detection control system, connecting the detection control system with the modulator via a speed-stabilizing circuit, and connecting the monochromator with the detection control system via a sampler and a sensor module. According to the present invention, the detection method of digital full period accumulation demodulation is adopted to carry out the simplification digital lock-in amplification processing on a sampling signal of each scanning wavelength point of the spectrograph, the multiplication and integration of a detection signal and two reference signals having 90-degree difference in the phase sensitive detection are realized by the full period signal absolute value accumulation, the low pass filtering is realized by the arithmetic average operation, and the coefficient correction is carried out by the square wave series to detect the amplitude of a spectral signal. Compared with the mode that the conventional grating scanning type spectrograph adopts a simulation lock-in amplification circuit detection system and a digital demodulation acquisition system, the circuit and algorithm are simple, the cost is low, the detection speed is fast, and the precision is high.