Abstract-We propose a compact, temperature-insensitive, all-silicon Mach-Zehnder interferometer (MZI) filter that uses the polarization-rotating asymmetrical directional couplers. Temperature sensitivity of the filter is less than 8pm/K for a wavelength range of 30 nm. The device achieves a reduced footprint by making use of different polarizations, which is made possible by the asymmetric directional couplers that act both as a splitter/combiner and as a polarization rotator. Simulation of the device shows that it can also be useful for gas sensing and bio-sensing applications with 3 times larger response to cladding changes while keeping a thermally robust behavior.

Abstract-We propose a method to make silicon optical finite impulse response filters tolerant to fabrication (waveguide geometry) and ambient thermal variations. We experimentally demonstrate a Mach-Zehnder interferometer filter with fabrication and thermal tolerance, both separately and together. The fabrication-tolerant device measurements show a 20-fold improved tolerance to systematic waveguide linewidth variations with a wavelength shift of <60 pm/nm linewidth change. The fabrication-and thermal-tolerant device is possible using orthogonal polarizations in the two arms. The fabricated device shows a shift of less than ±65 pm/nm and a thermal drift smaller than ±15 pm/K over a wavelength range of 40 nm. Simulations show that this concept can be extended to multichannel filters.

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The self-assembled monolayer FDTS (1H,1H,2H,2H-Perfluorodecyltrichlorosilane) is presented as suitable dewetting coating material for an electrowetting on dielectrics (EWOD) controlled silicon photonics switch deployed in fiber optic telecommunication systems. The anti-sticking characteristics of FDTS are compared to those of Polytetrafluoroethylene (PTFE) as most common dewetting coating for EWOD devices. It is shown that FDTS could outperform other materials such as PTFE when an extremely thin, long-term stable and uniform layer is required. In the specific case, FDTS is applied in vapor phase as anti-sticking coating to the active optical surface of the integrated silicon photonics switch thus enabling the EWOD driven liquid motion. The suitability of the coating is presented by contact angle measurements and durability tests carried out with the switching liquids. Finally, it is demonstrated by optical measurements that the FDTS coating has a neglectable influence on the optical switching performance.

A 16 × 16 silicon photonics switch circuit suitable for non-volatile operation has been realized. The switch circuit consists of dilated switch elements with liquid-controlled adiabatic waveguide couplers. The switch with crossbar architecture is compatible with a non-volatile electrowetting-on-dielectric (EWOD) system for optical actuation. The measured fiber-tofiber loss is less than 18.9 dB over the wavelength range 1500 nm to 1630 nm. At a wavelength of 1550 nm the loss is between 8.5 dB and 17.4 dB depending on the length of the light path. The crosstalk of the switch is better than −50 dB over the wavelength range 1500 nm to 1630 nm.