Amplitude squeezing by means of quasi-phase-matched second-harmonic generation in a lithium niobate waveguide

Abstract

We demonstrate that traveling-wave second-harmonic generation produces amplitude-squeezed light at both the fundamental and the harmonic frequencies. Quasi-phase-matched second-harmonic conversion efficiencies approaching 60% were obtained in a 26-mm-long single-mode LiNbO(3) waveguide with pulses from a mode-locked laser at 1.53 microm. The amplitude noise of the transmitted fundamental field was measured to be 0.8 dB below the shot-noise level, and the generated 0.765-microm harmonic light was measured to be amplitude squeezed by 0.35 dB. The conversion-efficiency dependence of the observed squeezing at both wavelengths agrees with theoretical predictions. Waveguide losses appear to degrade the squeezing, but the maximum observed squeezing is currently limited only by the available input power.

Blue Femtosecond Pulse Generated in Periodically Poled Lithium Tantalite

“…QPM makes nonlinear light wave mixing active in a more general stage through phase compensation with the modulation of second-order nonlinear susceptibility χ (2) of the medium [7,12], which usually leads to generating laser at a new frequency efficiently by sum frequency, difference frequency, or parametric amplification [14][15][16][17]. In addition, the QPM approach has applications in compression of a tunable-chirp pulse [18,19], generation of an optical solitons [20], and realization of optical bistability [21]. Other progresses, such as use of QPM material as a coherent THz radiation source and bright entanglement pair source have been emerged [22,23].…”

Pulsed-squeezed-light generation in a waveguide with second-subharmonic generation and periodic corrugation

“…For this reason we need a tool that allows us to reach nonlinear phase matching conditions for an arbitrary photonic structure. Periodic poling [39][40][41][42] of χ (2) susceptibility has occurred to be extraordinarily useful here and has resulted in the so-called quasi-phase-matched nonlinear interactions. Using this method even spectrally broadband two-mode nonlinear interaction with femtosecond pulses has become possible [43].…”

Generation of quantum‐entangled twin photons by waveguide nonlinear‐optic devices

“…Recently there has been remarkable progress in NLO devices for optical wavelength conversion through development of the quasi-phase-matched (QPM) NLO devices using periodically domain-inverted structures and waveguide structures [48]. Earlier work on quantum optics applications of waveguide QPM NLO devices includes squeezed light generation [49][50][51][52] and twinphoton generation (TPG) [52][53][54][55][56][57][58][59][60]. TPG devices have been extensively studied [61][62][63][64].…”