Trace-Gas Spectroscopy of Methane Using a Monolithically Integrated Silicon Photonic Chip Sensor

We present a monolithically integrated photonic sensor incorporating an on-chip 111- V laser, detector, sealed reference cell, and sensing waveguide capable of near-infrared absorption spectroscopy of methane near λ = 1651 nm. Sub-100 pprnv-Hz-1/2 sensitivities are demonstrated.