Investigation of polarization-pinning mechanism in deep-line-etched vertical-cavity surface-emitting lasers

Ghosh

Applied Physics Letters

et al. 2010

Polarization-resolved lateral-photoconductivity measurements are reported on device structures made of GaAs/Al(0.3)Ga(0.7)As quantum wells sandwiched between low-temperature grown GaAs(001) layers. The mesa device structures have long length (3 mm parallel to y) and narrow width (10 and 20 mu m parallel to x) in the (001) plane. For light incident along [001], the ground state light-hole exciton transition is much stronger for light polarization E parallel to x, compared to E parallel to y. The heavy-hole exciton transition shows a weaker polarization anisotropy of opposite sign, being stronger for E parallel to y. Through calculations based on the Bir-Pikus Hamiltonian, the observed in-plane optical polarization anisotropy is shown to arise from valence band mixing induced by anisotropic strain in the plane of quantum wells. (C) 2010 American Institute of Physics. [doi: 10.1063/1.3479501

Section: Polarization Sensitive Lateral Photoconductivity In Gaas/algsupporting

confidence: 57%

Polarization sensitive lateral photoconductivity in GaAs/AlGaAs quantum well based structures on low-temperature grown GaAs(001)

Ghosh

Applied Physics Letters

et al. 2010

MRS Internet j. nitride semicond. res.

“…This allows the nanometer scale fabrication of nitride devices. Focused ion beam (FIB) etching has also great potential for the post-processing of devices and has been successfully applied to achieve polarization control in red GaAs-based vertical cavity surface emitting lasers (VCSELs) [9,10]. In this report, we determine basic parameters for the FIB-etching of GaN.…”

Section: Introductionmentioning

confidence: 99%

Focused Ion Beam Etching of GaN

Flierl

White

Kuball

et al. 1999

Self Cite

We have investigated the use of focused ion beam (FIB) etching for the fabrication of GaN-based devices. Although work has shown that conventional reactive ion etching (RIE) is in most cases appropriate for the GaN device fabrication, the direct write facility of FIB etching -a well-established technique for optical mask repair and for IC failure analysis and repair -without the requirement for depositing an etch mask is invaluable. A gallium ion beam of about 20nm diameter was used to sputter GaN material. The etching rate depends linearly on the ion dose per area with a slope of 3.5x10

IEEE J. Select. Topics Quantum Electron.

“…FIB etching has previously been applied to VCSEL fabrication, primarily for modal control. Introducing mirror loss around a central region can give rise to a single-mode device [41], and polarization control can be achieved using targeted milling [42], and grayscale milling [43].…”

Section: B Photonic Crystal Vcselmentioning

confidence: 99%

Focused Ion Beam Nanopatterning for Optoelectronic Device Fabrication

Kim

Danner²,

Raftery

et al. 2005

Abstract-Recent photonic device structures, including distributed Bragg reflectors (DBRs), one-dimensional (1-D) or twodimensional (2-D) photonic crystals, and surface plasmon devices, often require nanoscale lithography techniques for their device fabrication. Focused ion beam (FIB) etching has been used as a nanolithographic tool for the creation of these nanostructures. We report the use of FIB etching as a lithographic tool that enables sub-100-nm resolution. The FIB patterning of nanoscale holes on an epitaxially grown GaAs layer is characterized. To eliminate redeposition of sputtered materials during FIB patterning, we have developed a process using a dielectric mask and subsequent dry etching. This approach creates patterns with vertical and smooth sidewalls. A thin titanium layer can be deposited on the dielectric layer to avoid surface charging effects during the FIB process. This FIB nanopatterning technique can be applied to fabricate optoelectronic devices, and we show examples of 1-D gratings in optical fibers for sensing applications, photonic crystal vertical cavity lasers, and photonic crystal defect lasers. Index Terms-Focused ion beam (FIB), lithography, photonic crystal, vertical cavity surface-emitting laser (VCSEL).