Optical parametric oscillations of 2 μm in multiple-layer bonded walk-off compensated KTP stacks

Abstract

Spatial walk-off can severely increase the threshold of critical phase-matched optical parametric oscillations (OPOs) and distort the output beam quality. With 16-layer KTP stacks for walk-off compensation, noncritical phase-match-like (NCPM-like) and quasi-phase-match-like OPOs with enhanced angular acceptance have been demonstrated based on two different KTP bonding orientations. In the NCPM-like composite, output pulse energy of 49 microJ has been achieved at pump energy of 523 microJ with pulse duration of 15 ns and repetition rate of 1 KHz. The OPO threshold as low as 254 microJ(44.6 MW/cm(2)) has been achieved.

Restoration of blurred images based on phase conjugation by using single second-order nonlinear parametric processes

“…Due to the parametric conversion, for the reflectivities of the resonator, given by R 1 = R 2 e 2gL , where g is the parametric gain coefficient, the back-propagating wave at λ i outside the resonator is eliminated [9]. Consequently, there is only one backward-propagating wave at λ pc .…”

“…Previously, it was demonstrated that for a fixed pump wavelength, two sets of signals and idlers can be simultaneously generated from a nonlinear composite consisting of adhesive-free-bonded (AFB) periodically-inverted KTiOPO 4 (KTP) plates [9]. Due to the presence of the signals and idlers having perpendicular polarizations, such a nonlinear process is insensitive to the polarization of the input beam.…”

Simultaneous Generation of Two Pairs of Stokes and Terahertz Waves from Coupled Optical Parametric Oscillations with Quasi-Phase-Matching

“…In recent years, it has been demonstrated that coupled optical parametric oscillations (OPOs) can simultaneously generate two pairs of signal and idler waves from periodically-inverted KTiOPO 4 (KTP) plates by a single pump wavelength [1,2]. The wavelengths for each pair of signal and idler waves satisfy quasi-phase-matching (QPM) conditions.…”

Optical parametric oscillations based on multiple-layer-bonded walk-off-compensated KTiOPO<inf>4</inf> stacks

“…However, shortening the crystal length in the WOC pair usually requires increasing the number of crystals to increase the total interaction length, which usually becomes non-practical for conventional WOC in independent crystals due to the increase of the inserting losses and the inconvenience in use. Recently, bonded WOC composites have attracted more and more attention because the monolithic WOC structure is easy to use and can significantly reduce the inserting losses [5,6]. More importantly, a large number of thin crystals can be used now in WOC to improve the device performance more significantly as well as the phase-matching type.…”

“…In Ref. [4,6], QNCPM OPO and dual-wavelength QPM OPO have been demonstrated in 16-layer PB-WOC KTP stacks. In Ref.…”