Oxide confinement and high contrast grating mirrors for Mid-infrared VCSELs

Abstract

International audienceA new mid-infrared (MIR) Vertical Cavity Surface Emitting Laser (VCSEL) structure is proposed. We have integrated to the VCSEL structure both an oxide aperture for lateral confinement, and a sub-wavelength high-contrast-grating top mirror. Upon the GaSb-based half-VCSEL, we have grown a metamorphic AlGaAs heterostructure to enable thermal oxidation and grating mirror fabrication steps. A methodology based on optimization and anti-optimization methods has been used to design the optical grating, with improved parameter tolerances regarding processing errors. Finally, we show the complete fabrication of an electrically-pumped MIR monolithic VCSEL structure implementing both oxide confinement and a subwavelength grating top mirror

Bound states in the continuum in symmetric and asymmetric photonic crystal slabs

“…To calculate it we used the phase-matching condition (9) with r (12) eff from Eq. (10). The blue mode in Fig.…”

“…The algebraic manipulations that lead to the definition of an effective reflection assume that some quantities [such as α −1 in Eq. (10)] are different from zero. As a consequence, some roots of the two-or three-wave resonance condition are not contained in the single-wave resonance condition given by Eqs.…”

“…Compared to three-dimensional (3D) PhCs, the simplified architecture of PhC slabs makes them attractive for on-chip integrated photonics [3,4]. In addition, their peculiar diffraction properties have been used in a wide variety of applications, including filters [5][6][7][8], vertical-cavity surfaceemitting lasers (VCSEL) [9][10][11], photovoltaics [12,13], thermal emission [14], and structural color generation [15].…”

Influence of low-contrast subwavelength grating shape on polarization characteristics of GaN-based light-emitting diode emissions

“…[6][7][8][9][10][11][12][13][14][15] In our previous study, we demonstrated highly polarized emission from a conventional GaN-based LED using an SWG in the 365-nm (UV) wavelength region. In the SWG, an eigenmode is defined as the solution of Maxwell's equations in the periodic refractive index distribution.…”

“…In the SWG, an eigenmode is defined as the solution of Maxwell's equations in the periodic refractive index distribution. [6][7][8][9][10][11][12][13][14][15] The grating side slope, which requires a very fine pitch, is sensitive to the fabrication conditions, including lithographic, crystal growth, evaporation, and etching conditions; the resultant grating shape is not always rectangular. With carefully chosen grating parameters, the destructive interference between the modes occurs and results in high reflectivity; hence, absorption of the material is one thing and the grating transmittance is the other.…”