Optical amplification high dynamic range nanosecond window signal-to-noise ratio measuring device

Abstract

The invention discloses an optical amplification high dynamic range nanosecond window signal-to-noise ratio measuring device. Comprising a coupling unit, a beam shrinking unit, a half-wave plate, a first spectroscope, a first attenuation sheet, a first measuring lens, a first detector, a combined crystal, a second spectroscope, a second attenuation sheet, a second measuring lens, a second detector, a third spectroscope, a reflector, a third measuring lens, a third detector, a fourth measuring lens, an optical fiber coupler, a transmission optical fiber and an optical amplifier. And a fourth detector, a high-speed oscilloscope and a data processing unit. The optical amplifier improves the sensitivity and the limit measurement capability of the fourth detector, and the combined crystal ensures that the second detector, the third detector and the fourth detector can work normally without being damaged under the action of high-power laser pulse (1.7 * 10 < 9 > W and 1.7 mJ and 1ps), so that the feasibility of high dynamic range expansion of the measurement device is provided. The first detector, the second detector, the third detector and the fourth detector can achieve dynamic range measurement of (109, 101 2), (106, 109), (103, 106) and (100, 103) respectively, and meanwhile accurate and complete high dynamic range measurement of 1012 is achieved.

Description

technical field [0001] The invention relates to parameter diagnosis of ultrashort laser pulses, and is a high dynamic range signal-to-noise ratio measuring device suitable for high-power nanosecond, picosecond and femtosecond pulses. Background technique [0002] The signal-to-noise ratio of ultrashort pulses is an important parameter in ultrashort and ultraintense laser devices. With the development of laser technology, the focusable power density of the laser focal spot can reach 10 20 W / cm 2 Or higher, the noise will also increase. When the focused spot is used in related physical experiments such as plasma physics, laser-matter interaction, etc., it is hoped that the focused power density of the leading edge noise is less than 10 12 W / cm 2 In order to avoid the pre-plasma generated by frontal noise and matter, which will affect the interaction between the subsequent laser main pulse and matter. When the signal-to-noise ratio is used to evaluate this technical index,...

AI Technical Summary

Problems solved by technology

[0007] The problem to be solved by the present invention is the difficulty that the existing signal-to-noise ratio measurement technology scheme based on the parallel operation mode of photodetectors cannot realize the further improvement of the dynamic range

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