High performance InP ring resonator for new generation monolithically integrated optical gyroscopes

Abstract

An InP ring resonator with an experimentally demonstrated quality factor (Q) of the order of 10(6) is reported for the first time. This Q value, typical for low loss technologies such as silica-on-silicon, is a record for the InP technology and improves the state-of-the-art of about one order of magnitude. The cavity has been designed aiming at the Q-factor maximization while keeping the resonance depth of about 8 dB. The device was fabricated using metal-organic vapour-phase-epitaxy, photolithography and reactive ion etching. It has been optically characterized and all its performance parameters have been estimated. InP waveguide loss low as 0.45 dB/cm has been measured, leading to a potential shot noise limited resolution of 10 °/h for a new angular velocity sensor.

Ultra-Low Loss Large Area Waveguide Coils for Integrated Optical Gyroscopes

“…The optimum ARW is 28°/ hr/ √ Hz and occurs at 15m. State of the art RMOGs can theoretically achieve on the order of 10°/hr/ √ Hz [13], [15], with a smaller footprint. For comparison, we calculated the sensitivity of a coil with state of the art loss of 0.1dB/m, and use the maximum length with the same footprint of 30 meters.…”

Recent advances in miniaturized optical gyroscopes

“…Silica-on-silicon and silicon nitride technologies allow the fabrication of resonators with very low loss [41]- [43], but LiNbO 3 [44], glass [45,46], silicon [47], polymers [48], and InP [49,50] are also used. Along with these fully passive ring resonators, some configurations, including an optical amplifier to compensate losses, have been also proposed and experimented [51,52].…”

“…The design, fabrication and characterization of a ring resonator with radius of 13 mm, coupled to a single bus waveguide and fabricated with low loss InGaAsP/InP rib waveg- [70] * Theoretical value with P PD = 1 mW; η = 0.9; τ int =10 s. uide are reported in [73,50]. For the realized rib waveguide, with an etch depth of 0.3 µm and a width of 2 µm, a propagation loss for the fundamental quasi-TE mode reaching the record value of 0.45 dB/cm has been measured.…”

“…The resonator has a quality factor equal to 0.97×10 6 [50]. If it is used as the sensing element of an RMOG, the target resolution of 10 • /h can be reached with an average power at photodiodes input equal to 13.84 mW.…”

“…• Hybrid integration allowing the selection of the best technology for each component InP gyroscopeon-a-chip [50] • The monolithic integration enhances the device compactness and immunity to external disturbances (e.g., vibrations)…”