Upconversion blue laser by intracavity frequency self-doubling of periodically poled lithium tantalate parametric oscillator

Abstract

We report a design for upconversion 435 nm blue lasers based on simultaneously fulfilling the nonlinear processes of optical parametric oscillation (OPO) and second-harmonic generation (SHG) in a 7.9 mum periodically poled lithium tantalate (PPLT). The uncoated 15-mm-long PPLT device exhibits a low threshold of 150 mW and a differential slope efficiency of 22.6%, rendering 56 mW blue generation when pumped by a pulsed 532 nm green laser with an average power rating of 400 mW. These observations were attributed to a quasi-phase-matching (QPM) structural design with a 75% domain duty cycle to ensure the concurrence of frequency doubling with the first-order QPM-OPO PPLT device via the second-order QPM-SHG process.

Multiwavelength generation from multi-nonlinear optical process in a 2D PPLT

“…It has been reported that SFG and DFG can be generated in a PPLN when facilitated by a cascaded process [16]. For nonlinear photonic crystals, a blue light can be generated from an OPG-signal in a SHG process using a PPLT with a square lattice [17] or a PPLT with a hexagonal lattice [5]. In some studies, it has been demonstrated that a broadband wavelength can be generated in a hexagonal nonlinear photonic crystal [18,19].…”

Angular-tuning of optical parametric generation efficiency in 2D periodically poled lithium tantalate

“…The 2D-PPLT crystal used in this study is shown in figure 4. It is fabricated by the electrical poling technique 17,18 . The poled regions are circular and periodically organized according a square lattice with a grating period Λ x = Λ y = 8.52 μm.…”

Generation of green frequency comb from chirped χ(2) nonlinear photonic crystals

“…It involved a use of a 20 mm-long periodically poled lithium tantalate (PPLT) as the gain medium. 30 Our two-step poling procedure for fabricating the PPLT devices can be found in Ref. 31.…”