For all the recent advances in integrated lithium niobate photonic circuits, one big component has remained frustratingly difficult to integrate which is lasers.
Long haul telecommunication networks, data centre optical interconnects and microwave photonic systems all rely on lasers to generate an optical carrier used in data transmission. Lasers are stand-alone devices and external to the modulators. This makes whole system more expensive and less stable and scalable.
Scientists from Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS) have developed the first fully integrated high-power laser on a lithium niobate chip. This paved the way for high-powered telecommunication systems, fully integrated spectrometers, optical remote sensing and efficient frequency conversion for quantum networks.
The study was published in the journal Optica. Scientists used small but powerful distributed feedback lasers for their integrated chip. The lasers sit in small wells or trenches etched into the lithium niobate and deliver up to 60 milliwatts of optical power in the waveguides fabricated in the same platform, on chip.
Scientists combined the laser with a 50 gigahertz electro-optic modulator in lithium niobate to build a high-power transmitter. Scientists combined thin-film lithium niobate devices with high-power lasers by using an industry-friendly process. This research represents a key step towards large-scale, low-cost and high-performance transmitter arrays and optical networks. Scientists are also aiming to increase the laser’s power and scalability for more applications.