Seeded optical parametric generation in CdSiP₂ pumped by a Raman fiber amplifier at 1.24  µm.

Area of Science:

• Optics and Photonics
• Mid-Infrared (MIR) Technology
• Nonlinear Optics

Background:

• Optical parametric generators (OPGs) are crucial for generating tunable laser light.
• Developing efficient and tunable MIR sources is essential for various spectroscopic applications.
• Non-critical phase-matching offers advantages in crystal alignment and power handling.

Purpose of the Study:

• To demonstrate a seeded optical parametric generator (OPG) for tunable MIR radiation.
• To investigate the performance of a cadmium silicon phosphide (CSP) crystal in a seeded OPG configuration.
• To achieve efficient generation of mid-infrared radiation using a fiber laser system.

Main Methods:

• Utilized a 13 mm long cadmium silicon phosphide (CSP) crystal cut for non-critical phase-matching.
• Pumped the OPG using a nanosecond-pulsed, MHz repetition rate Raman fiber amplifier at 1.24 µm.
• Employed a filtered, continuous-wave fiber supercontinuum source at 1.72 µm as the seed.

Main Results:

• Successfully generated tunable radiation in the 4.2-4.6 µm range.
• Achieved up to 0.25 W of mid-infrared (MIR) idler power.
• Demonstrated a total pump conversion efficiency of 42% (combined signal and idler).

Conclusions:

• The seeded OPG system using CSP crystal is effective for generating tunable MIR radiation.
• The system demonstrates high pump conversion efficiency, suitable for practical applications.
• This work contributes to the advancement of efficient MIR light sources.