A Tunable Mid-Infrared Solid-State Laser with a Compact Thermal Control System

Abstract

Tunable mid-infrared lasers are widely used in laser spectroscopy, gas sensing and many other related areas. In order to solve heat dissipation problems and improve the environmental temperature adaptability of solid-state laser sources, a tunable all-fiber laser pumped optical parametric oscillator (OPO) was established, and a compact thermal control system based on thermoelectric coolers, an automatic temperature control circuit, cooling fins, fans and heat pipes was integrated and designed for the laser. This system is compact, light and air-cooling which satisfies the demand for miniaturization of lasers. A mathematical model and method was established to estimate the cooling capacity of this thermal control system under different ambient environments. A finite-element model was built and simulated to analyze the thermal transfer process. Experiments in room and high temperature environments were carried out and showed that the substrate temperature of a pump module could be maintained at a stable value with controlled precision to 0.2 degrees, while the output power stability of the laser was within ±1%. The experimental results indicate that this compact air-cooling thermal control system could effectively solve the heat dissipation problem of mid-infrared solid-state lasers with a one hundred watts level pump module in room and high temperature environments.

State-of-the-Art Laser Gas Sensing Technologies

“…The last paper in this section, authored by D. Yu, Y. He, K. Zhang, Q. Pan, F. Chen, and L. Guo, is about a compact thermal control system for a tunable mid-infrared solid-state laser, which could be used to improve environmental temperature adaptability and solve heat dissipation problems for mid-infrared lasers [12].…”

Mid-infrared optical parametric oscillation spanning 3.4–8.2 μm in a MgF2 microresonator

“…An optical parametric oscillator (OPO) composed of discrete and equally-spaced optical frequency components can act as an excellent multi-wavelength source with high fineness, leading to the improvement of acquisition rate and resolution for molecular spectroscopy [5][6][7]. The MIR OPO is particularly important for access to molecular fingerprints and thus provides a powerful tool for the chemical composition analysis in biochemistry, medicine, optical sensing and material science [8,9]. Conventional mid-infrared OPOs can be achieved via nonlinear crystals pumped by fiber lasers or solid-state lasers, but they usually suffer from a complicated structure and high SWaP (size, weight and power) because of bulky components involved, which seriously limit their outfield applications [10,11].…”