Herbert D'heer

A Compact All-Silicon Temperature Insensitive Filter for WDM and Bio-Sensing Applications

We propose a compact, temperature-insensitive, and all-silicon Mach-Zehnder interferometer filter that uses the polarization-rotating asymmetrical directional couplers. Temperature sensitivity of the filter is 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 three times larger response to cladding changes while keeping a thermally robust behavior.

Maximizing Fabrication and Thermal Tolerances of All-Silicon FIR Wavelength Filters

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.

Broadband and non-volatile liquid controlled silicon photonics switch

A broadband and non-volatile liquid controlled silicon photonics switch is proposed. The measured crosstalk is less than -22dB and -12dB over 100nm wavelength range for bar and cross state, respectively. The insertion loss is less than 1dB.

New materials for modulators and switches in silicon photonics (Conference Presentation)

In this presentation we will report on our recent work on new materials that can be monolithically integrated on high-index contrast silicon or silicon nitride photonic ICs to enhance their functionality. This includes graphene and other 2D-materials for realizing compact electro-absorption modulators and non-linear devices, ferroelectric materials for realizing phase modulators and adiabatic couplers for realizing bistable switches.