Two-color Semiconductor Mode-locked Laser system for Multiphoton Imaging Applications.

We demonstrate an all-semiconductor mode-locked laser system consisting of two external cavity mode-locked lasers operating at wavelengths 834 nm and 974 nm which use semiconductor optical amplifiers as gain media. The two-color laser system emits picosecond pulses with average powers of 25 mW and 60 mW resulting in peak powers exceeding 100 W and 80 W respectively. Synchronized output pulse trains from the lasers with a repetition rate of 282 MHz exhibit a relative timing jitter of 7.3 ps. Fiber coupled output from the laser system delivers an ideal output beam with TEM00 mode profile. Peak power densities >1 GW/cm2 can be achieved by focusing the output beam to a smaller spot with 4 µm diameter, which is crucial for applications that requires excitation of optical nonlinearities.

Multi-dimensional data transmission using inverse-designed silicon photonics and microcombs.

The use of optical interconnects has burgeoned as a promising technology that can address the limits of data transfer for future high-performance silicon chips. Recent pushes to enhance optical communication have focused on developing wavelength-division multiplexing technology, and new dimensions of data transfer will be paramount to fulfill the ever-growing need for speed. Here we demonstrate an integrated multi-dimensional communication scheme that combines wavelength- and mode- multiplexing on a silicon photonic circuit. Using foundry-compatible photonic inverse design and spectrally flattened microcombs, we demonstrate a 1.12-Tb/s natively error-free data transmission throughout a silicon nanophotonic waveguide. Furthermore, we implement inverse-designed surface-normal couplers to enable multimode optical transmission between separate silicon chips throughout a multimode-matched fibre. All the inverse-designed devices comply with the process design rules for standard silicon photonic foundries. Our approach is inherently scalable to a multiplicative enhancement over the state of the art silicon photonic transmitters.

Direct chip-scale optical frequency divider via regenerative harmonic injection locking.

A novel optical frequency division technique, called regenerative harmonic injection locking, is used to transfer the timing stability of an optical frequency comb with a repetition rate in the millimeter wave range (∼300GHz) to a chip-scale mode-locked laser with a ∼10GHz repetition rate. By doing so, the 300 GHz optical frequency comb is optically divided by a factor of 30× to 10 GHz. The stability of the mode-locked laser after regenerative harmonic injection locking is ∼10-12 at 1 s with a 1/τ trend. To facilitate optical frequency division, a coupled opto-electronic oscillator is implemented to assist the injection locking process. This technique is exceptionally power efficient, as it uses less than 100µW of optical power to achieve stable locking.