Liquid-crystal electric tuning of a photonic crystal laser

Abstract

An electrically tuned nematic liquid-crystal (LC) infiltrated photonic crystal (PC) laser is demonstrated. This PC laser represents an emerging class of nanoscale optical adaptive devices enabled by the convergence of nonlinear optical materials, electronics, and fluidics that promise increased functionality and utility over existing technologies. A LC cell is constructed by encasing the PC laser between two indium tin oxide glass plates, which serve as the modulating electrodes. Applying a voltage across the cell realigns the LC, modifies the laser cavity's optical path length, and blueshifts the lasing wavelength.

Giant gain enhancement in photonic crystals with a degenerate band edge

“…We will show that this implies a gigantic increase in the density of states (electromagnetic modes) and the group index near a DBE compared to what happens near an RBE. This leads to also to Q-factors that are orders of magnitude higher than the same for their RBE counterparts, namely 5 Q N [30], with N being the number of unit cells of the dielectric stack.…”

“…An important class of high Q-factor structures is formed by slow-wave resonators based on the regular band edge (RBE) of the wavenumber-frequency dispersion diagram relative to photonic crystals, whose simplest architecture is a periodic stack of dielectric layers, with one dimensional periodicity [1][2][3]. More elaborate designs of nanocavities adopted Silicon heterostructures [4], liquid crystals [5] technologies and demonstrated improved Q-factor compared to previously reported designs. The use of photonic crystals resulted in enhanced amplification properties for low-threshold lasing [2,6], enhanced directionalwave propagation through magneto-optical effects [7][8][9], nonlinear optics [10] and quantum processing [11].…”

“…The layer that includes an active material, and thus intrinsic gain, can be realized by either layers of quantum wells [40], Raman scattering mechanisms [41] or layers doped with active materials like Erbium [42] for example. A possible implementation of anisotropic layers can be carried out utilizing liquid crystals, for instance, possessing tunable anisotropic properties [5,43].…”

Directed self‐assembly of single quantum dots for telecommunication wavelength optical devices

“…The ability to control the dot emission would be extremely beneficial in this regard. However, spectral matching currently relies on cavity design, with various fine tuning methods used after fabrication to bring the dot and cavity mode into resonance [79][80][81][82][83][84][85].…”

Microfluidic interferometer

“…First, fluids are a mobile phase, which allows for the infiltration of any void in a device and tunability through motion of the fluid body. As well as refractive index modulation, the fluids may incorporate a gain medium, 5 be a liquid crystal 6 or be multiphase, all of which add to the functionality of the device. Second, the refractive index contrast between a fluid and the surrounding air can be quite large, providing much higher phase delays for interferometric devices in a more compact space than can be achieved by regular electro-optic modulation.…”