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

Abstract

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.

Expanding the Silicon Photonics Portfolio With Silicon Nitride Photonic Integrated Circuits

“…All of this results in effective index deviations from the designed value, which is a critical design parameter for interferometric devices such as Mach-Zehnder Interferometers (MZI), ring resonators and Arrayed Waveguide Gratings (AWGs). It is well known that ∼1 nm width (thickness) variation produces 1 nm (1.4 nm) spectral shift for such interferometric components [66]. This subject is discussed in more detail in section IV for the case of dispersive spectrometers.…”

“…Typically 1 • C change in temperature shifts the spectrum of SOI wavelength filters by 70 pm. To circumvent this, either active tuning is deployed or temperature insensitive SOI-based devices are designed [65], [66], [110]- [112] to ensure fixed wavelength operation. The large thermo-optic effect is used to good effect for implementing low-speed thermo-optic switches [113], couplers with arbitrary coupling ratios [114], tunable filters [30] and to compensate fabrication-induced phase errors on delay lines or ring resonator based interferometric filters.…”

Optical temperature sensor with enhanced sensitivity by employing hybrid waveguides in a silicon Mach-Zehnder interferometer

“…In a temperature sensor based on an unbalanced MZI with the two arms denoted as arm 1 and arm 2, the temperature sensitivity S, i.e., the interference wavelength shift with respect to the temperature T, is given by [27] …”

Ultrahigh Temperature-Sensitive Silicon MZI with Titania Cladding

“…In case of silicon photonic Mach-Zehnder interferometer (MZI), there were reports showing the way to reduce the TDWS of MZI without using a cladding with a negative TOC (Uenuma and Moooka, 2009;Guha et al, 2010;Dwivedi et al, 2013). TDWS of silicon MZI was shown to be reduced by using different widths of waveguide (Uenuma and Moooka, 2009;Guha et al, 2010) or by using different polarization (Dwivedi et al, 2013) in each of the MZI arm, respectively.…”

“…TDWS of silicon MZI was shown to be reduced by using different widths of waveguide (Uenuma and Moooka, 2009;Guha et al, 2010) or by using different polarization (Dwivedi et al, 2013) in each of the MZI arm, respectively. The difference in each of the MZI arm can induce a different temperature-dependent phase change for the each arm, resulting reduction in TDWS of MZI.…”