Widely tunable efficient intracavity quasiphase-matched midinfrared generation

Abstract

We describe in this letter a novel approach to obtain a tunable midinfrared (mid-IR) laser output. By applying quasiphase-matched difference frequency generation in a periodically domain inverted LiNbO3 crystal placed inside a Cr3+:LiSAF laser cavity, more than 50 mW of mid-IR output was generated using only 1.8 watts of red diode or dye laser pumping. Wavelength tuning of the mid-IR signals from 3.3 to 4.2 μm was demonstrated by tuning only the wavelength of the Cr3+:LiSAF emission, without the need to reorient the LiNbO3 crystal for domain period adjustment.

New methods for fabricating patterned lithium niobate for photonic applications

“…These include traveling wave modulators [1,2], optical switch arrays [3], wavelength converters [4,5], and tunable mid-IR coherent light sources [6]. The large refractive index of LiNbO 3 (nB2:2) also makes it an attractive material for 2D linear photonic crystals [7].…”

Pseudospectral time-domain methods for modeling optical wave propagation in second-order nonlinear materials

“…Frequency conversion processes in second-order ͓ (2) ͔ nonlinear materials such as LiNbO 3 have been explored for a variety of optical communications, signal processing, data-storage, and sensing applications that rely on components such as wavelength routers, add-drop multiplexers, tunable coherent light sources, and all-optical switches. [1][2][3][4] Many of these nonlinear processes have been demonstrated in waveguiding structures designed with one-dimensional (1-D) quasi-phase-matching (QPM) techniques 5 to enhance the frequency conversion efficiency. Coupled-mode theory and beam propagation methods [6][7][8][9][10] have played important roles in the analysis and design of such structures.…”