Mid-infrared gas filled photonic crystal fiber laser based on population inversion

Andrew M Jones,Brian R Washburn,François Couny,A V Vasudevan Nampoothiri,Kristan L Corwin,Wolfgang Rudolph,Tobias Fiedler,Rajesh Kadel,Natalie V Wheeler,Fetah Benabid,Amarin Ratanavis

doi:10.1364/oe.19.002309

Abstract

We demonstrate for the first time an optically pumped gas laser based on population inversion using a hollow core photonic crystal fiber (HC-PCF). The HC-PCF filled with 12C2H2 gas is pumped with ~5 ns pulses at 1.52 μm and lases at 3.12 μm and 3.16 μm in the mid-infrared spectral region. The maximum measured laser pulse energy of ~6 nJ was obtained at a gas pressure of 7 torr with a fiber with 20 dB/m loss near the lasing wavelengths. While the measured slope efficiencies of this prototype did not exceed a few percent due mainly to linear losses of the fiber at the laser wavelengths, 25% slope efficiency and pulse energies of a few mJ are the predicted limits of this laser. Simulations of the laser's behavior agree qualitatively with experimental observations.

Highlights

The need for portable, tunable lasers in the mid-infrared is compelling
In this paper we report on the demonstration of a new class of optically pumped gas laser based on population inversion
Realization of the first gas fiber laser based on population inversion holds great promise for coherence generation applications as well as for engineering high power, portable and robust, all fiber mid-IR sources in the future

Summary

Introduction

The need for portable, tunable lasers in the mid-infrared (mid-IR) is compelling. This eyesafe spectral region offers high atmospheric transmission essential to applications such as remote sensing and space-based terrestrial imaging and communications. A variety of optically pumped gas lasers have been demonstrated, from the earliest CH3F [8], CO2 [9], and OCS [10], to alkali vapor [11], CO [4, 5], HBr [6], C2H2 and HCN [7] Some of these mid-IR lasers can be pumped via ro-vibrational overtones at wavelengths in the telecommunication bands where commercial pump sources are well established and readily available. A variety of nonlinear optical phenomena [14] have been demonstrated using HC-PCF including the development of a gas-filled fiber Raman laser [15] and a multi-octave spanning Raman frequency comb [16]. These fibers can be spliced to solid-core fibers, creating compact, robust sealed gas cells that can readily be integrated into devices [21]

Fiber specifics

Laser configuration

Experimental results and discussion

Modeling results

Conclusions