Optimization of electrically tunable VCSEL with intracavity nematic liquid crystal

Abstract

Abstract:We optimize the wavelength tuning range of a Vertical-Cavity Surface-Emitting Laser with an intracavity layer of nematic Liquid Crystal (LC-VCSEL) lasing around 1.3 μm. The tunability is obtained by applying voltage to the liquid crystal layer, which esentially is to vary the refractive index from the extraordinary to the ordinary. We achieve 71.6 nm continuous tuning (without mode hopping) with liquid crystal thickness of about 3.2 μm. We investigate the impact of ambient temperature on the LC-VCSEL tuning range and show that mode-hop tuning can be achieved in the temperature range from −10 • C to 50 • C where the LC is in nematic phase.

Liquid-Crystal Alignment by a Nanoimprinted Grating for Wafer-Scale Fabrication of Tunable Devices

“…Many demonstrations of passive LC-based tunable Fabry-Perot (FP) interferometers filters were reported in the 1990s [2]- [3]- [4]. However, despite a renewed interest for active LC-based photonic devices [5]- [6]- [7] and the demonstration of an optically-pumped tunable LC-VCSEL in 2011 [8], the fabrication of electrically driven tunable active devices has not been demonstrated yet, as this implies to combine LC alignment with electrode management at a micro-scale size. Alignment of liquid crystal molecules is indeed mandatory in these polarization-sensitive devices.…”

Anisotropic Transverse Confinement Design for Electrically Pumped 850 nm VCSELs Tuned by an Intra Cavity Liquid-Crystal Cell

“…Experimental data are available for VCSELs, overlayed by an LC reservoir [8], [9], [10], which is very different compared to an intracavity tunable device. Hitherto two different approaches have been proposed: wafer fusion [11], [12] and hybrid approach [13], [14], both lacking experimental demonstration of an electrically driven device.…”

“…C. Belmonte et al presented in 2015 a theoretical study of a 1.3 µm electrically driven LC-VCSEL that highlighted a thermal limitation at 50 °C using E7 [11]. More recently, the same group published further model details.…”

Light Propagation in Confined Nematic Liquid Crystals and Device Applications

“…Lasers were demonstrated by means of a novel approach to generate actively Q-switched laser pulses based on an integrated waveguide chip and an LC cell in the deformed helix ferroelectric (DHF) mode, able to behave like an active Q-switch modulator under a wide range of repetition frequencies [40]. Vertical cavity surface-emitting laser, including LC as a tuning medium, was also reported [41].…”