title: Characteristics and crosstalk of optical waveguides fabricated in polymethyl methacrylate polymer circuit board.
abstract: Electro-optical circuit boards should provide simple and cost-effective coupling techniques and crosstalk levels of less than -30  dB. A dicing saw was used to create waveguide grooves with a surface roughness of less than 183 nm in a 1.6-mm-thick polymethyl methacrylate polymer (PMMA) substrate. The buried optical waveguides were made from SU-8 in a PMMA substrate covered with a 1-mm PMMA sheet. The propagation loss for a 500  μm×570  μm straight waveguide was 0.9 dB/cm at 1310 nm. The coupling between parallel waveguides was measured at separation distances from 45 to 595 μm. The crosstalk was less than -40  dB for 65-mm-long waveguides. This fabrication method shows potential for dense optical interconnects with very low crosstalk.
authors.forename: Hanan H
authors.initials: HH
authors.lastname: Hamid
authors.forename: Christian E
authors.initials: CE
authors.lastname: Rüter
authors.forename: David V
authors.initials: DV
authors.lastname: Thiel
authors.forename: Thomas
authors.initials: T
authors.lastname: Fickenscher