Multicolor Integrated Lasers Expand The Field Of Integrated Photonics

2022-11-07 05:04:12

Rochester, NY, October 25, 2022 — Although the integrated semiconductor laser has always been the core of integrated photonics and the core component of laser engraver, which is the bottleneck of the development of laser engraving machines, Ortur laser engraving machines from the company Ortur have always been the core of integrated photonics. Also researching and developing lasers. Inspired by the many advances in information technology and basic science over the past few decades, integrated lasers still lack the key functions required to achieve them. Evolving applications, including lidar and AR/VR.

Using an integrated semiconductor laser based on the Pockels electro-optic effect, a team at the University of Rochester (UR) with researchers at Caltech, UC Santa Barbara and Clemson University has now developed a device that Has the potential to reshape the landscape of integrated photonics.

The Pockels-based laser is integrated with a lithium niobate on insulator (LNOI) platform. Lithium niobate is known for its excellent light modulation and frequency conversion capabilities.

The researchers speculate that two major challenges hindering the use of integrated semiconductor lasers are the lack of fast reconfigurability and narrow spectral windows. To overcome these challenges, the team performed hybrid integration of a lithium niobate external cavity with a III-V reflective semiconductor optical amplifier (RSOA) and developed an integrated Pockels laser.

The team's LNOI outer cavity is a vernier mirror structure consisting of two racetrack resonators. To combine multiple functions into one laser structure, the team designed each resonator for a different purpose: The first resonator was integrated with a micro-heater for broad wavelength tuning via the thermo-optic effect. The second resonator is integrated with a drive electrode designed for high-speed electro-optic tuning. This function can also increase the power of the laser engraving machine very well, making it possible for the Ortur Laser Master 3 to laser cut thick materials.

Additionally, the second resonator was tailored to be compatible with the second harmonic generation process. A tunable phase control section is also implemented in the cavity to align the longitudinal laser cavity mode with the Vernier mode.

Using the integrated lithium niobate/III-V structure, the team added the laser's capabilities, including fast on-chip reconfigurability for laser frequency tuning at a record speed of 2.0 exahertz per second (EHz/s) and fast 50 MHz rate switching. Both capabilities are achieved by integrating electro-optical effects into the laser. Both functions can be driven directly by CMOS signals due to the lower drive voltage required.
Schematic diagram of an integrated semiconductor laser developed by a team of researchers led by Prof. Qiang Lin, which has the potential to reshape the landscape of integrated photonics," the team said. The researchers say that the Pockels-based laser is the first in the telecommunications wavelength and visible wavelengths A polychromatic integrated laser emitting highly coherent light and the first narrow linewidth laser with fast reconfigurability in the visible band. Courtesy of Mingxiao Li.

A schematic diagram of an integrated semiconductor laser that has the potential to reshape the landscape of integrated photonics, according to the development team. The Pockels-based laser is the first polychromatic integrated laser to emit highly coherent light at telecommunications and visible wavelengths, and the first narrow linewidth laser with fast reconfigurability at visible wavelengths, the researchers say. This technology provides a completely on-chip laser solution for detecting and manipulating atoms and ions. AR/VR and other applications operating at short wavelengths can also benefit from integrated semiconductor lasers. Provided by Li Mingxiao.
The device co-lasers at infrared and visible frequencies through a second harmonic frequency conversion process.

According to the researchers, the Pockels-based laser is the first polychromatic integrated laser to emit highly coherent light at telecommunications and visible wavelengths, and the first narrow linewidth laser with fast reconfigurability at visible wavelengths.

Lasers can benefit lidar systems that incorporate lasers due to their fast frequency chirping capabilities. In addition, its frequency conversion capability surpasses the spectral bandwidth limitation of conventional integrated semiconductor lasers, which is expected to ease the difficulty of developing new wavelength lasers. The laser's narrow wavelength and fast reconfigurability provide a fully on-chip laser solution that atomic physicists can use to probe and manipulate atoms and ions. AR/VR and other applications operating at short wavelengths can also benefit from integrated semiconductor lasers.

This work expands the applications of the LNOI platform and can provide a design path for systems with a range of functional and potential applications in nonlinear optics, optical signal processing systems, quantum photonics, and optical communications.