The Realization Of Medium Wave Infrared Laser Power Stabilization System

The traditional photoelectric detection system consists of photoelectric detector, preamplifier circuit and data acquisition control circuit, photoelectric detector plays an important part in information conversion and transmission in the system. The main performance parameters of photoelectric detector includes integral sensitivity, spectral sensitivity, frequency sensitivity, quantum efficiency, normalization detectivity, noise equivalence power and so on. With the development of material science and the semiconductor technology, a new technical target to the scale of photoelectric detector has been put forward. There are two key points in the calibration of photoelectric detector, which are the light beam quality and the performance of standard detector. Under the new situation, the emergence of cryogenic radiometer provides a new way to scale the detector. Due to the superior performance of cryogenic radiometer, when using the system with cryogenic radiometer, standard light source with good performance should match with it to achieve highly precision calibration measurement.Cryogenic radiometer is a kind of precision instruments of measuring absolute optical radiation power with low temperature superconducting technology, it is widely used in scaling absolute spectrum responsivity of mid-wave infrared detector. With the new impact to scaling absolute spectrum responsivity of mid-wave infrared detector brought by cryogenic radiometer, measurement experiments have raised new requirements to the output light power’s stability of mid-wave infrared laser. At present, domestic research on high output power stability of mid-wave infrared laser still cannot meet the demands of cryogenic radiometer to the source.Focused on the requirements of mid-infrared measurement and application fields, this article proposed a design of a high stability Mid-IR laser power system. Firstly, this paper described the research significance of the subject, then introduced in detail about the laser power stable external modulation method and analyzed the acousto-optic modulation principle. Based on this, this paper introduced a design of the matching control circuit, with which the Mid-IR laser output light intensity can be adjusted in real time to make the optical output power be stable. Finally, the article enumerates the measurement data of the laser’s output power, detailed analyzes the noise source and suppression method in the system. By use of this method, the stability of the 3391 nm laser’s output power can be limited in eight over ten thousandths, which can satisfy the measurement of band very well.