5:45 PM - 6:00 PM
▲ [14p-2D-12] Sub-kHz linewidth lasers using integrated Si3N4 ring resonators
Keywords:Lasers,Linewidth,Resonators
Frequency discriminators are attractive devices for reducing integrated laser linewidths for coherent communication systems and high purity microwave photonic systems. Standard diode lasers have MHz level linewidths and a few recent results have pushed this below 100 kHz. Typical on chip devices allow for a few cm of delay in a Mach Zehnder (MZI) configuration, but larger delays are needed for integrated devices. Here, we show a fully integrated Si3N4 ring resonator used as an optical discriminator with a sensitivity better than a 10 meter delay line interferometer. We utilize the Pound-Drever-Hall (PDH) technique to characterize the resonator bandwidth of 6.7 MHz (30 million loaded Q) and improve the linewidth of a state of the art commercial laser by locking to the waveguide coupled resonator. We measure a minimum frequency noise power spectral density of 30 Hz2/Hz at a 10 kHz offset.