Measured radiation effects on InGaAsP/InP ring resonators for space applications

Area of Science:

• Photonics and Optical Engineering
• Space Technology and Satellite Systems
• Materials Science for Radiation Environments

Background:

• Photonic ring resonators are key components for satellite payloads, enabling functions like filtering and sensing.
• High Q-factor ring resonators offer enhanced performance in Resonant Micro Optic Gyroscopes (RMOGs) compared to other technologies.
• Evaluating radiation effects on these components is critical for space qualification.

Purpose of the Study:

• To investigate the impact of gamma radiation on high Q InGaAsP/InP ring resonators for the first time.
• To assess the radiation hardness of InP-based ring resonators for potential space applications.

Main Methods:

• Irradiation of an InGaAsP/InP rib waveguide ring resonator (530 mm² footprint) with Co60 gamma rays up to a total dose of 320 krad.
• Characterization of the resonator's Q-factor and extinction ratio (ER) before and after irradiation.
• Analysis of resonance peak shifts (detuning) as a function of absorbed radiation dose.

Main Results:

• A mean variation of approximately 13% in Q-factor and 4% in ER was observed after 320 krad irradiation.
• The initial Q-factor was 1.36 × 10⁶ and ER was 6.24 dB.
• A linear red-shift of the resonance peak was observed, reaching a maximum detuning of 810 pm.

Conclusions:

• The study demonstrates the resilience of high-Q InP-based ring resonators to significant gamma radiation doses.
• These findings support the potential use of InP ring resonators in space systems and subsystems, particularly for RMOGs.
• The observed minimal performance changes indicate good radiation tolerance for space environments.