High efficiency surface emitting lasers using blazed grating outcouplers

Abstract

Grating coupled surface emitting lasers with rectangular as well as blazed grating outcouplers were investigated. Horizontal cavity InGaAs/AlGaAs laser oscillators, with two rectangular first order surface gratings as feedback elements, were integrated with single detuned rectangular or blazed second order gratings as surface output couplers, using electron beam lithography and chemically assisted ion beam etching. Superior differential quantum and surface emission efficiencies of 56% and 84%, respectively, were measured for lasers with optimized blazed output couplers.

An out-of-plane grating coupler for efficient butt-coupling between compact planar waveguides and single-mode fibers

“…To enhance the efficiency of grating couplers (avoid coupling to substrate), a blazed or parallellogram-shaped grating [17] is sometimes used. However, this makes simulation and fabrication much more difficult and the behavior of a blazed grating in our structure is yet unknown.…”

High-resolution proximity lithography for nano-optical components

“…They define a class of optical components which have found versatile applications e.g. in spectrometers [8,9] since the early days of optical instrumentation [10,11] and are essential building blocks for modern optical systems [12][13][14][15][16], light sources [17][18][19][20][21], and optical communication devices [22][23][24]. Recently, many novel optical nanostructures with unique functionality have appeared: Wire grid polarizers (WGP) [25][26][27] can achieve polarization discrimination over a broad spectral range and even for deep ultra-violet (DUV) wavelengths.…”

Fabrication of surface gratings in GaAs and AlGaAs by electron beam lithography and chemically assisted ion beam etching

“…The main differences in these models are the formatted reaction products. Hagberg et al" summarized all these models, applied them to CAIBE and presented after some simplifications an equation (1) for the calculation of the etch rate h of GaAs: (1) where Yo and Ysci3 are the sputter yields of GaAs bulk material and the formed chloride, respectively. 0ci is the chlorine coverage, j is the ion beam current density, P20 is the initial kinetic ion energy, c is the fraction of the initial kinetic energy that reaches the target, q is the electric charge of the ions, p is the number of atoms per unit volume, and 4 is the collision angle.…”