Solution-processed chalcogenide glass for integrated single-mode mid-infrared waveguides

Abstract

Chalcogenide glass materials exhibit a variety of optical properties that make them desirable for near- and mid-infrared communications and sensing applications. However, processing limitations for these photorefractive materials have made the direct integration of waveguides with sources or detectors challenging. Here we demonstrate the viability of two complementary soft lithography methods for patterning and integrating chalcogenide glass waveguides from solution. One method, micro-molding in capillaries (MIMIC), is shown to fabricate multi-mode As(2)S(3) waveguides which are directly integrated with quantum cascade lasers (QCLs). In a second method, we demonstrate the ability of micro-transfer molding (µTM), to produce arrays of single mode rib waveguides (2.5 µm wide and 4.5 µm high) over areas larger than 6 cm(2) while maintaining edge roughness below 5.1 nm. These methods form a suite of processes that can be applied to chalcogenide solutions to create a diverse array of mid-IR optical and photonic structures ranging from <5 to 10's of µm in dimension.

Sub-micrometer soft lithography of a bulk chalcogenide glass

“…NIL can be used with hard (quartz, silicon, metal, or tungsten carbide, etc.) molds, with which imprinting has been demonstrated for optical waveguides (4.5−6 μm wide and 2 μm high) into As 2 Se 3 film by using Si mold during hot embossing [6], submicrometer nano-cone arrays into Ge 15 As 15 Se 17 Te 53 bulk glass by using Si mold [7], sub-micrometerperiod wiregrid polarizer into Sb-Ge-Sn-S bulk glass by using SiC mold [8], micrometer-size anti-reflection surfaces at the ends of infra-red (IR) As 2 S 3 chalcogenide glass (ChG) fibers by using Ni mold [9], and sub-micrometer diffraction grating in Ge 20 As 20 Se 14 Te 46 bulk glasses by using Si, SiO 2 and Ni molds [10].…”

“…Similarly PDMS imprinting of micrometer-size waveguides into thermally evaporated thin films As 2 S 3 has been demonstrated [12,13]. Tsay et al [14] used solution of As 2 S 3 glass dissolved in propylamine, which was forced into micro-channels of PDMS mold and after baking-off and removing PDMS 'mold' micrometer-size single-mode waveguides (2.5 μm wide and 4.5 μm high) have been prepared. The main advantages of PDMS as a mold material are its good compliance and easy peel-off from ChG after cooling, i.e.…”

Solution phase driven As2S3 chalcogenide films: Optical and picosecond nonlinear optical properties

“…The error in the thickness measurement was estimated to be AE 2.5%. The¯lms prepared from 0.6 g/ml solution are usually thicker and can be used to fabricate optical components such as micro-lenses or waveguides with high sag (hight of the structure) value (16-18 m), 19,26 whereas thin¯lms of the order of sub-microns can be prepared by 0.4 g/ml or less loading solution. Hence, thick and thin¯lms could be prepared from these solutions while varying the spin speed and concentration of the solution.…”

“…17,18 These merits clearly establish that solution phase chalcogenide glass processing o®ers several advantages for realizing optical components for the IR optics, particularly for mid-infrared waveguide development. 19 Arsenic tri-sul¯de (As 2 S 3 ) possesses easy synthesis route and also has an excellent photosensitivity. 20 In this paper, we demonstrate solution processed As 2 S 3 chalcogenide¯lms as an alternative route for¯lm deposition.…”

Substrate-blind photonic integration based on high-index glass materials

“…Work by us as well as others have shown that deposition of these amorphous materials can be performed on different substrate materials and geometries (e.g., curved surfaces) using techniques including thermal evaporation, magnetron sputtering, pulsed laser deposition, chemical vapor deposition, or solution processing [1][2][3][4][5][6][7][8][9][10][11][12][13] . Most of these deposition methods can be carried out at relatively low substrate temperatures (typically below 250 °C).…”