Laser trimming of the operating wavelength of silicon nitride racetrack resonators

Abstract

We demonstrate the possibility of post-fabrication trimming of the response of nitrogen-rich silicon nitride racetrack resonators by using an ultraviolet laser. The results revealed the possibility to efficiently tune the operating wavelength of fabricated racetrack resonators to any point within the full free spectral range. This process is much faster than similar, previously presented methods (in the order of seconds, compared to hours). This technique can also be applied to accurately trim the optical performance of any other silicon photonic device based on nitrogen-rich silicon nitride.

Thermo-optic tuning of silicon nitride microring resonators with low loss non-volatile $$\hbox {Sb}_{2}\hbox {S}_{3}$$ phase change material

“…The TO coefficient of 57 is approximately 1.00 x 10 , while the TO coefficient of the deposited stoichiometric -PECVD SiNx-films 58 is 1.00 x 10 . The TO coefficient for ZnS- is fit to be 2.35 x 10 and 9.375 x 10 before annealing and after annealing respectively.…”

“…In this section, we investigate the permanent trimming 57 (non-volatile tuning) of RRs integrated with a crystalline cell using a C-band in-plane CW laser by tuning the resonant wavelength at low pump powers: 10, 12.55 and 14 dBm and high powers: 17 and 21 dBm. In order to estimate the power applied to the material in the waveguide, a loss of dB per GC is taken into account and an additional loss of dB was experimentally measured for the introduction of a power attenuator in the system, resulting in an optical waveguide power level of −5.9, −3.35, dBm for the low pump powers, and 1.1, dBm for the high pump powers.…”

A Review of Capabilities and Scope for Hybrid Integration Offered by Silicon-Nitride-Based Photonic Integrated Circuits

“…By exposing a section of an RR for a few seconds (or some minutes, depending on its free spectral range and on the power of the laser), it is possible to switch its output, shifting its resonances towards shorter wavelengths (blue shift). Experimentally, a shift of −6.95 nm of the resonant wavelength has been demonstrated after exposing with a UV laser (244 nm wavelength and 40 kJ/cm 2 fluence) a 126 µm long section of an RR with FSR of 6.15 nm [218]. reprinted with permission from [192], ©2016 American Chemical Society.…”

UV-written silicon nitride integrated optical phased arrays

“…In this manuscript, we propose the use of a technique that has been used to permanently change the behavior of silicon oxide and silicon nitride devices by UV irradiation [18] (λ = 244 nm) in order to create 1D waveguide integrated antenna structures with radiating elements that are periodically patterned within the waveguide core. We have previously demonstrated [19] the post-fabrication UV laser trimming of nitrogen-rich silicon nitride ring resonators operating in the short-wave infrared spectral region (around 2 um), capable of obtaining a change of -2 x 10 -2 in the refractive index of the material while using a laser beam with a spot diameter of 7 um for a few seconds. The induced refractive index change is caused by the structural rearrangement of the bonding configuration of the Si-N bonds and the release of hydrogen [20] from the SiNx film that is associated with high energy generated by the UV light, causing Si-H and, the N-H bonds to break.…”