Injection-seeded optical parametric amplifier for generating chirped nanosecond pulses

Abstract

We constructed an optical parametric amplifier with BiBO crystals, which was injection seeded by a phase-modulated cw beam in the 1,040-1,070 nm region. Two-stage pre-amplification by Yb-doped fibers were implemented for stable injection to the OPA. The frequency chirp in the OPA pulse was actively controlled by adjusting the RF wave for the phase modulation and its synchronization to the OPA firing. Down/up chirps with up to 500 MHz shift were demonstrated. The output pulse energy was ~40 mJ, which is sufficient for future application of frequency conversion and coherent population transfer.

Dispersion‐Engineered Super‐Gain Parametric Amplification in Nanoscale Optical Cavities

“…The reason for this is that at such frequencies, a super-nonlinear response is induced via a simultaneous enhancement of the accumulated electric energy density and the second-order nonlinearity. This occurrence is explained in Table 2 where energy density and nonlinearity are computed based on Equation ( 20)- (25). For f p ¼ 540 THz, the energy density and the second-order nonlinearity are concurrently high, which maximizes the rate of energy transfer to the input wave and enables strong OPA even under such a short-interaction length.…”

“…Our goal was to examine whether there was an optimum pump-wave frequency that maximized the intracavity energy density and the medium nonlinearity at the same time, such that OPA could occur under a much lower pump-wave amplitude that was practically easier to attain. [23][24][25] We would focus on the numerical analysis of nanoscale semiconductor cavities (Figure 4) with resonance frequencies in the near-infrared region, where optical nonlinearity often had a spectral peak.…”