Numerical models of broad-bandwidth nanosecond optical parametric oscillators

Abstract

We present three new methods for modeling broad-bandwidth, nanosecond optical parametric acillators in the plane-wave approximation. Each accounts for the group-velocity differences that determine the operating linewidth of unseeded optical parametric oscillators, and each allows the signal and idler waves to develop from quantum noise. The first two methods are liased on split-step integration methods in which nonlinear mixing and propagation are calculated separately on alternate steps. One method relies on Fourier transforming the fields between t and w to handle propagation, wiih mixing integrated over a AZ step: the other transforms between z and IC, in the propagation step, with mixing integrated over At. The third method is based on expansion of the three optical fields in terms of their respective longitudinal empty cavity modes, taking into account the cavity boundary conditions. Equations describing the time development of the mode amplitudes are solved to yield the time dependence of the three output fields. These plane-wave models exclude diffractive effects, but can he readily extended to include them.

Mid-infrared laser with 1.2 W output power based on PPLT

“…The threshold of OPO is lower than 1 W. When the pump power is 20 W, Utilizing split-step Fourier method [12], we simulate the pulse-pumped single-resonant OPO. The result of experiment is in accordance with the simulation prediction ( Figure 2).…”

Effect of idler absorption on efficiency of optical parametric oscillators

“…There are numerical models for OPOs demonstrated in former researches. [12][13][14] But these models cannot exactly meet our requirements. In the following, a modified model is applied to describe the effect of idler wave absorption in OPOs.…”

Numerical analysis for single-frequency nanosecond optical parametric oscillators and optical parametric amplifiers

“…The emphases are focused on the spectral bandwidth of the output beam and conversion efficiency of these devices. The second section takes a simple review of the model we used here, introduced by Smith [11][12][13]. Numerical model for OPOs and OPAs has been found long before [14].…”

“…The early model ignores the depletion of the pump wave in optical parametric process, which is impossible in reality. The depletion, transverse electric field distribution of three mixing waves has been considered in subsequent models developed by Smith et al [11][12][13]. The third section demonstrates OPOs operated under different conditions.…”