Trace-gas Spectroscopy of Methane using a Monolithically Integrated Silicon Photonic Chip Sensor

We present a monolithically integrated photonic sensor incorporating an on-chip III-V laser, detector, sealed reference cell, and sensing waveguide capable of near-infrared absorption spectroscopy of methane near λ = 1651 nm. Sub-100 ppmv∙Hz-1/2 sensitivities are demonstrated.