Research Projects

The demand for ultrafast mid-infrared(mid-IR) laser sources is ever growing, with broad range of applications including environmental monitoring, homeland security and medical diagnostics. According to a report published by Future Market Insights Inc, the mid-IR lasers market was valued at $1.1 billion in 2023, and is expected to reach a value of $2.8 billion by 2033, at a compound annual growth rate of ~9.9%, during the forecast period (2024 - 2033), indicating the great economic impact of this niche technology. Typical mid-IR coherent sources include solid-state lasers, fiber supercontinuum, quantum cascade lasers and optical parametric oscillators. While majority of these sources operate at discrete wavelengths, OPOs are both spectrally and temporally versatile and can operate at wavelength where conventional laser sources are unavailable. In this research proposal, we aim to develop an ultrafast femtosecond OPO based on a relatively new nonlinear material, Cadmium Silicon Phosphide (CSP). The CSP OPO operates at 6 μm in the mid-IR wavelength range, which is of great interest for the application mentioned above. Typically, mid-IR nonlinear crystals require pumping beyond 2 μm. However, CSP is a unique nonlinear material which can be pumped using the matured laser technology based on Nd:YAG/Yb-fiber lasers operating at 1 μm to generate mid-IR radiation at wavelengths as long as 6 μm. Hence, the design and characterization of the CSP crystals for the linear and nonlinear absorption at the pump wavelength, design and development of the synchronously-pumped femtosecond CSP OPO, performance characterization of the CSP OPO along with wavelength tuning and power scaling and investigation of power scaling limitations are the main objectives of this proposed research. The successful realization of this project results in the first indigenously developed mid-IR coherent source at 6 μm and the optical characterization of the CSP crystals provides key understanding of the nonlinear material properties for threshold optimization and power scaling.