Ultra-high-efficiency tunable silicon photonic filter

Abstract

Optical tunable filters play a key role in silicon photonic integrated circuits. Highly energy-efficient tunability and a wide continuous tuning range are strongly desired for silicon photonics filters. All-optically thermo-optic (TO) tunable devices based on the light absorbers integrated close to the silicon structure as localized heaters have attracted increasing attention because optical heaters, compared with electrical ones, can greatly reduce thermal loads and heat leakage for the device. They provide a new approach to implementing high-efficiency TO tuning with a fast response. In this work, we propose and experimentally demonstrate an on-chip all-optically tunable filter based on a suspended silicon microdisk resonator with an ultra-compact optical heater, which is a platinum absorber deposited directly on the top of the ridge waveguide. Attributed to the novel optical pumping scheme, ultra-small device size, and suspended waveguide structure, an ultra-high tuning efficiency of 37.70 nm/mW is achieved. Only 1.405 mW pump power is required to tune the single-resonance filter over a wide spectral range of ∼54.5 nm. The demonstrated tunable optical filter has the advantages of high tuning efficiency, compact footprint, and simple fabrication processes, which has significant applications for on-chip all-optical systems.

Analog Wavelength Locking in an Optical Single-Sideband Transmitter of a Millimeter-Wave Radio-Over-Fiber Link Featuring a Micro-Ring Resonator and a Heat-Pump-Controlled Laser

“…Researchers have investigated different approaches to overcome the challenges of MRR temperature dependence [22]. Existing approaches mostly fall into two categories: (1) approaches that permanently reduce the temperature dependence of MRRs to very low or near-zero values by altering their structural and/or material properties, so-called athermal solutions, and (2) the ones that actively control their instantaneous material and/or geometric properties by means of thermo-optic-(TO) [23,24] or electro-optic-(EO) effectenabling elements. While athermal solutions might effectively eliminate the temperature dependence of the MRR, it might not guarantee its relative wavelength alignment with the laser of an RoF transmitter.…”