Advances in narrow-linewidth continuous wave semiconductor disk laser pumped optical parametric oscillators

Abstract

The paper reports on M Squared Lasers' recent work in the field of narrow-linewidth, continuous wave (CW) optical parametric oscillators (OPO) that utilise the semiconductor disk laser (SDL) format for intra- and extracavity pumping schemes. For the experimental investigation, InGaAs quantum well gain structures were employed to produce compact SDLs which were subsequently used to pump OPOs based on periodically poled lithium niobate (PPLN). Using the intracavity architecture, a compact, CW, narrow-linewidth OPO was developed, capable of delivering up to 250 mW of narrow-linewidth idler output power (at ~3.3 μm). The SDL maintained stable single longitudinal mode operation and the spectral bandwidth of the OPO output was measured to be <0.14nm. A full discussion of the experimental set-up and results will be presented, together with a review of the potential issues and limitations in pursuing the development of intracavity pumped, single frequency OPOs. In addition to the intracavity work, extracavity approaches will also be discussed and their performance compared to those produced from the intracavity device. For the purpose of pumping singly resonant extracavity PPLN OPOs, high power (>15W), single frequency SDLs were developed using single- and multichip configurations. The extracavity OPO pumped by these sources delivered up to 950 mW of idler output power, with a minimum threshold of 2.4 W and tuning range from 2.8 μm to 3.6 μm. Further details of the high power, single frequency SDLs as well as the extracavity OPO will be discussed, with specific focus on the advantages and disadvantages of multi-chip and single-chip arrangements for single frequency SDLs.