Direct laser writing of relief diffraction gratings into a bulk chalcogenide glass

Abstract

We inscribed relief diffraction gratings with periods of 6, 14, and 24 μm into the surface of Ge15Ga3Sb12S70 bulk glass by the material's ablation using a femtosecond λ = 800 nm Ti:sapphire pulsed laser. The laser writing was done with sample implemented on a computer-controlled stage employing surface-to-beam alignment, laser power, and raster pattern control. Pulse energies of 1.5, 3.0, and 4.5 μJ were focused on spot diameter of 1.5 μm, resulting in channel widths, measured on the surface, of around 4, 5, and 6 μm and depths up to 1.7 μm. The first-order diffraction efficiency of the fabricated gratings was up to 10% at 650 nm. We have also fabricated a "composite" grating combining the three relief diffraction gratings inscribed in the same position, but with a mutual tilt. The composite grating provides complex multidirectional diffraction of the light in accordance with geometrical arrangement and grating period of all the gratings inscribed. We propose practical applications of femtosecond pulsed-laser surface patterning, for example, surface-relief diffraction microgratings integrated at the ends of multimode mid-IR chalcogenide optical waveguides or on the surfaces of bare core chalcogenide glass optical fibers used for chemical sensing. © 2012 Optical Society of America

Sub-micrometer soft lithography of a bulk chalcogenide glass

“…at room temperature (RT). NIL is a competing technology to traditional optical lithographic techniques [15], direct laser writing (DLW) [16], holography [17], and focused ion beam (FIB) milling [18], all of which are costly, time-consuming and complex. It is the DLW which has been gaining lots of interest especially for its versatility in patterned shapes and variety of materials being used [19].…”

“…It is the DLW which has been gaining lots of interest especially for its versatility in patterned shapes and variety of materials being used [19]. Soft lithography in comparison with direct laser machining into the chalcogenide bulk glasses, for example as in [16], brings several advantages especially in reduced surface roughness of the patterns, low-cost facility contrary to fs-lasers, capabilities of extremely fast large-area and repeatable mass-production due to its ability of multiple replications of cheap PDMS softmold from costly master-mold. Also, rather often neglected, the ChGs, in form of thin films and bulks, suffer from burning when exposed to fs-lasers and the composition is altered.…”

Chalcogenide amorphous nanoparticles doped poly (methyl methacrylate) with high nonlinearity for optical waveguide

“…The thickness of the film was controlled to be 7 µm by adjusting the rotating speed. We fabricated a waveguide structure array on the hybrid polymer film using femtosecond laser writing technique 13 . Figure 6 shows the optical microscopic image of the as-obtained waveguide array.…”

In-Situ and Ex-Situ Characterization of Femtosecond Laser-Induced Ablation on As2S3 Chalcogenide Glasses and Advanced Grating Structures Fabrication

“…Among these manufacturing technologies, femtosecond lasers has opened up new applications and possibilities in the bulk glass materials due to its limited heat affected zone, very high flexibility and noncontact process, which has been used in the manufacturing of Nd:LuVO 4 , Ge-Sb-Se,As 2 Se 3 , Tm:YVO 4 and Nd:GLSG (neodymium doped gallium lanthanum sulfide glass) [10,11,12,13,14]. Femtosecond direct writing methods in the case of chalcogenide bulk glass and fibers have been used to make 3D holographic recordings, bulks of gratings and waveguides [15,16,17,18]. In addition, long-period gratings are an important part of optical communication systems for optical filtering and mode conversion, optical gain, and sensing applications.…”