Dynamic holography in a broad-area optically pumped vertical GaAs microcavity

Abstract

A broad-surface-area vertical GaAs microcavity was operated as an adaptive holographic film. The cavity mirrors were transparent to high-energy (millijoules per square centimeter) hologram writing pulses at a wavelength of 730 nm that generated optically pumped gain gratings in a 1-m-thick active layer of GaAs. The gain gratings were probed with a low-intensity (mW) tunable laser at wavelengths near the GaAs band edge in the high-reflectance bandwidth of the cavity Bragg mirrors. When the structure was designed with low mirror reflectances ͓(R 1 R 2) 1/2 ϭ 90%͔ to operate below the lasing threshold, the cavity resonance bandwidth was sufficiently broad to permit homogeneous hologram readout over a large (several square millimeters) area. Diffraction efficiencies of approximately 10% were predicted and approached experimentally. These results represent a first step toward the realization of a holographic vertical-cavity surface-emitting laser structure.

Bragg thickness criterion for intracavity diffraction gratings

“…For the 1-m-thick sample of Ref. 12 we get Q FP ϭ 4.8, and we can see from Fig. 8 that the order 1 relative intensity has decreased to 5 ϫ 10 Ϫ2 .…”

Bragg diffraction in thin 2D refractive index modulated semiconductor samples

“…The thickness is also an issue as it must not be too large if an integrated device is wanted, although the diffraction regime associated with thin crystals is a Raman-Nath regime involving multiple diffracted beams. Besides the already wellknown simple [2][3][4] and double resonance [5][6][7][8][9] in a Fabry-Perot cavity, a new approach using slow light at the band edge of a one-dimensional photonic crystal (1D-PC) was recently demonstrated to overcome these difficulties, first in photopolymers [10] and then in semiconductor Bragg reflectors [11]. Results are especially attractive in the latter case due to the high index contrast of Bragg reflectors.…”

Efficient Bragg-like operation of intracavity low-efficiency plane gratings

“…Most of the time, such a device is operated at normal incidence to avoid the walk-off of the read beam in the Fabry-Perot cavity. [7][8][9][10][11][12][13] In that case, only the read beam is Fabry-Perot resonant, and the diffracted beams are all enhanced in the same manner. To favor a unique diffraction mode, we use Bragg incidence and tune the resonator accordingly.…”