SU-8 rib waveguide Bragg grating filter using composite stamp and solvent-assisted microcontact molding technique

摘要

We present a simple fabrication technique using a hydropho-nbic composite elastomer for patterning an SU-8-based rib waveguidenBragg grating filter via solvent-assisted microcontact molding u0001SAMIMu0002.nThe proposed technique utilizes a two-layered composite stamp made ofnpolydimethylsiloxane and hard polydimethylsiloxane, which enables bothnthe rib waveguide and surface relief grating structure to be patternednsimultaneously. The SAMIM method realizes patterning at ambient tem-nperatures with the weight of the mold applying all the pressure neces-nsary. By allowing the mold to absorb solvent when in contact with thenpolymer, the solvent dissolves or swells the polymer’s surface, creatingnthe desired pattern. This composite mold successfully demonstrates thenSAMIM creation of the SU-8 rib waveguide and gratings, paving the waynfor a facile and efficient reproduction of a polymeric rib waveguide grat-ning filter. Based on experimental results, the stamp demonstrates annoperational life span in excess of 10 successful replications, utilizing anBragg grating test pattern with a grating period of u0001492 nm, a depth ofnu0001250 nm, and a total length of 12 mm. The resulting waveguides show anband-rejection gain of −17 dB at the center wavelength of 1545 nm andna 3-dB bandwidth of 2.5 nm