High-flux photon-pair source from electrically induced parametric down conversion after second-harmonic generation in single optical superlattice

Abstract

We present here a possible high-flux photon-pair source constructed by single lithium niobate optical superlattice (OSL) with a combined quasi-periodically and periodically poled structure, which is from the principle of electrically induced parametric down conversion (PDC) after second-harmonic generation (SHG), predicted by the united theory developed in this paper, in which SHG, PDC and electro-optic (EO) effect are comparably treated as two-order nonlinear effects. In the OSL, the e-polarized fundamental frequency photons are first converted to double frequency ones with the same polarization; then the PDC process is triggered by EO effect when the fundamental frequency photons are almost exhausted; finally, the double frequency photons are converted again to a series of two-photon pair of fundamental wave. It is demonstrated that at 100 degrees C, in a 20.2mm long OSL with a 30V / mm applied electric field, a 100MW/cm(2), 1080 nm laser beam can be translated to a flux of high-purity two-photon pairs with a conversion efficiency close to 100%; and for a longer OSL the pump intensity can be further lowered. The device can also act as an ultra-low field electro-optic switch.

Frequency Doubling and Polarization Coupling Using Birefringence-Phase-Matching and Quasi-Phase-Matching Simultaneously in Single Optical Superlattice

“…Not only single optical parametric processes, such as SHG [1][2][3], sum-frequency generation (SFG) [4], and optical parametric oscillation (OPO) [5,6], but also coupled parametric processes, and notably third-harmonic generation [7][8][9], have been achieved in these materials with high efficiency. In recent years, cascaded frequency conversion and electro-optic (EO) coupling (or polarization coupling) have received much research attention [10][11][12][13][14][15][16][17][18][19][20]. We found in these cases only two or three mismatches of wave vector were compensated, which were only special cases included in our united theory [16], however the general case including six mismatches of wave vector is still unsolved.…”

“…In recent years, cascaded frequency conversion and electro-optic (EO) coupling (or polarization coupling) have received much research attention [10][11][12][13][14][15][16][17][18][19][20]. We found in these cases only two or three mismatches of wave vector were compensated, which were only special cases included in our united theory [16], however the general case including six mismatches of wave vector is still unsolved. In order to solve the problem, we present in this paper that general case of cascaded SHG and polarization coupling can be realized by using BPM and QPM simultaneously in an OSL.…”

Optical Triode Based on Electrically Induced Quadratic Cascading in an Optical Superlattice

“…To discuss our principle we first introduce a wave coupling theory describing the united effect of EO, SHG and PDC in a PPLN or/and quasi-periodically poled LN (QPPLN) OSL in Ref. [32,33]. Fig.…”

“…( 1)-( 4) in Ref. [32,33] to find a OSL that satisfies our requirement. As well known, the key to QPM in OSL is to design a structure that provides a set of reciprocal vectors to compensate for the mismatches of wave vectors owing to the dispersion of refractive index.…”

“…( 1)-( 4) in Ref. [32,33], that in general, there exist six mismatches of wave vectors relative to SHG, PDC and EO effects. For our purpose, however, we need only to take account of one compensation for .…”