Injection seeded tunable mid-infrared pulses by difference frequency mixing

TL;DR

This paper demonstrates the generation of tunable, narrow-linewidth, high-energy mid-infrared pulses via difference frequency mixing of injection-seeded near-infrared lasers in nonlinear crystals, with potential applications in spectroscopy.

Contribution

It introduces a new method for producing tunable mid-infrared pulses with narrow linewidth and high energy using injection-seeded difference frequency mixing.

Findings

Mid-infrared pulses with 0.4-1 mJ energy per pulse.

Tuning wavelength from 3142 to 4806 nm.

Linewidth of 1.4 GHz confirmed by gas absorption line.

Abstract

We report on the generation of nanosecond mid-infrared pulses having frequency tunability, a narrow linewidth, and a high pulse energy. These pulses are obtained by frequency mixing between injection-seeded near-infrared pulses in potassium titanyl arsenate crystals. A continuous-wave external cavity laser diode or a Ti:sapphire ring laser is used as a tunable seeding source for the near-infrared pulses. The typical energy of the generated mid-infrared pulses is in the range of 0.4-1 mJ/pulse. The tuning wavelength ranges from 3142 to 4806 nm. A narrow linewidth of 1.4 GHz and good frequency reproducibility of the mid-infrared pulses are confirmed by observing a rovibrational absorption line of gaseous carbon monoxide at 4587 nm.