Near infrared integrated photonic switches for portable quantum sensors

Abstract

Abstract A novel integrated semiconductor photonic switch, based on carrier-induced refractive index changes, has been designed and fabricated for use at near infrared wavelengths (890-920 nm, 750-780 nm and 745-775 nm). These switches are intended for use in quantum sensors which rely on the spectroscopy of caesium, rubidium or potassium atoms respectively. The beam-steering properties of the 890-920 nm device are presented and its extinction ratio measured to be 13.4 dB. This measurement was limited by coupling efficiency. Subsequent changes made to the testing equipment include the implementation of an automated testing routine. This new experimental setup will facilitate the full characterisation of the 890-920 nm device and the newly fabricated optical switches, designed for operation in the wavelength ranges 750-780 nm and 745-775 nm respectively.