Second-harmonic generation in GaAs ’’stack of plates’’ using high-power CO2 laser radiation

Abstract

Efficient wide-band high-power generation of CO2 laser second-harmonic radiation is reported using a ’’stack-of-plates’’ approach to phase match the interaction in GaAs. A long collinear interaction length is achieved by using a series of {111} GaAs crystalline plates at Brewster’s angle, each one coherence length thick, oriented so as to alternate the sign of the nonlinear polarization in each consecutive plate. The peak second-harmonic power generated was 60 kW at 5.3 μm using 3 MW of mode-locked pump power with a stack of 12 GaAs plates. 420

Growth of mm-thick orientation-patterned GaAs for IR and THZ generation

“…Unlike lithium niobate, GaAs is not ferroelectric, so a different scheme must be implemented to produce the patterned structures for QPM. Periodic inversion has been achieved using stacks of GaAs plates with alternating orientation in configurations where the plates were discrete [3,4], bonded [5,6], or bonded and epitaxially regrown [7]; however, it is challenging to maintain periodicity in the stack and to access short periods. An alternative approach to creating patterned structures requires first producing a layer of inverted (antiphase) GaAs on a GaAs substrate.…”

Second harmonic generations in aperiodic optical superlattices with finite width and in one-dimensional defective photonic crystals made of nonlinear optical materials

“…In the conventional method, phase-matching (PM) condition is required for gaining high conversion efficiency [1,2], however, the PM condition brings a big restriction to the choice of natural birefringent material. Another scheme is the so-called quasi-phase matching (QPM) [3,4], which can significantly diversify the class of nonlinear optical materials [5][6][7][8][9][10][11][12][13]. Some groups of researchers have successfully achieved the design of aperiodic optical superlattices (AOSs) for multiple wavelength second harmonic generations (SHGs) [14,15].…”

Nonlinear optical effects in rotationally-twinned crystals: An evaluation of CdTe, ZnTe and ZnSe

“…On discutera les avantages potentiels en Several alternative methods of achieving phasematching other than birefringence have been proposed [4][5][6][7], following the original suggestions of Bloembergen [8,9]. Experimental interest in these techniques [10] has been revived in the last several years [11][12][13][14] Recently, we have demonstrated [15,16] that enhanced nonlinear optical ef'ects may be generated in rotationally-twinned crystals. In this paper, the physical basis of these effects will be described and an evaluation of several useful 43m materials will be given.…”

“…[2] [11,13,14], it is useful to consider methods whereby rotationally-twinned crystals could be used to obtain multiple coherent domains in a single crystal. Figure 4 illustrates three possibilities which are currently being investigated in our laboratory.…”

“…Included in the list are birefringent phase-matchable crystals as well as nonbirefringent 43m materials which may be employed in periodic phase matching schemes. The data were compiled from a number of sources, including the surveys by Kurtz [25,26], Byer [27], and Akhmanov et al [28], the book by Zernike and Midwinter [2], nonlinear coefficients for GaAs and CdTe as adopted by Thompson et al [13] and Piltch et al [14], respectively, data on InAs and GaSb from Wynne and Bloembergen [29], and unpublished data we have obtained on damage thresholds for proustite (Ag3AsS3) and ZnSe.…”