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.

Liquid Crystals into Planar Photonic Crystals

“…much higher than the LC conductivity), the applied electric field is screened out of the infiltrated holes where the field distribution results to be nonuniform, so that only a small part of the LC molecules experience a field large enough to reorient. Several approaches have been thus proposed to compensate for these electric-field screening effects and to maximize the electric tunability of the PhC devices, such as deposing the electric contacts or a conducting glass directly on the PhC surface (Maune et al, 2004;Haurylau et al, 2006a-b). Therefore, before setting-up the electric tuning of our infiltrated PhCs, we characterized the electrical conductivity of the InP-based heterostructure (see Sect.…”

“…1, the optical response of a PhC infiltrated with nematic LCs can be adjusted by applying an external electric field that modifies the molecule orientation inside the holes (Maune et al, 2004;Alagappan et al, 2006;Haurylau et al, 2006a-b;Anderson et al, 2007;Reyes et al 2008). Since semiconductor materials like InP are usually characterized by small electro-optic coefficients (Scrymgeour et al, 2003), this latter mechanism is particularly interesting when relatively moderate electric fields are used for the tuning of the optical properties of semiconductor-based planar PhCs.…”

“…In particular, the potential of PhC infiltration with nematic liquid crystals (LCs) has been largely demonstrated for one-, two-and three-dimensional (1D, 2D and 3D) PhCs. Therefore, besides their classical fields of application, LCs are also having a strong impact in the PhC field (Busch & John, 1999;Yoshino et al, 1999b;Leonard et al, 2000;Kang et al, 2001;Shimoda et al, 2001;Kubo et al, 2002;Mertens et al, 2002;Gottardo et al, 2003;Mertens et al, 2003;Schuller et al, 2003;Weiss & Fauchet, 2003;Busch et al, 2004;Du et al, 2004;Kubo et al, 2004;Martz et al, 2004;Maune et al, 2004;Kosmidou et al, 2005;Lourtioz et al, 2005;Maune et al, 2005;Weiss et al, 2005a-b;Ferrini et al, 2006;Haurylau et al, 2006b;.…”

“…Among the numerous techniques that have been proposed, infiltrating the air pores of a PhC with a synthetic organic material that has a tunable refractive index (e.g. liquid crystals, polymers, liquids, and liquid dispersions of colloidal quantum dots) has proved to be one of the most promising approaches for both trimming and tuning (Busch & John, 1999;Yoshino et al, 1999b;Leonard et al, 2000;Kubo et al, 2002;Gottardo et al, 2003;Mertens et al, 2003;Schuller et al, 2003;Maune et al, 2004;Mingaleev et al, 2004;Weiss et al, 2005a;Erickson et al, 2006;Ferrini et al, 2006;Haurylau et al, 2006a-b;Intonti et al, 2006;Martz et al, 2006;Tomljenovic-Hanic et al, 2006;van der Heijden et al, 2006a;Barthelemy et al, 2007;Smith et al, 2007;Tay et al, 2007). The effect of infiltrating a PhC with a low refractive index material is qualitatively shown in Fig.…”

Demonstration of air-guided quantum cascade lasers without top claddings

“…The possibility of performing intra-cavity spectroscopy or sensing [9,10,11,12,13,14,15,16,17] with quantum cascade lasers is an alternative intriguing approach [18,19,20,21]. In such a scheme, the laser would react to a material (gas, fluid, or solid particles) deposited within or on the surface of the laser by detuning its emission wavelength or increasing its threshold current density.…”