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This paper proposes an electrothermally-actuated circular pyramidal kirigami microscanner with a millimeter-range low-power lens drive for endoscopic biomedical applications. A variation of Japanese origami art, kirigami involves creation of out-of-plane structures by paper cutting and folding. The proposed microscanner is composed of freestanding kirigami film on which the spiral-curved thermal bimorphs are strategically placed. The kirigami microscanner is electrothermally transformed into an out-of-plane circular multistep pyramid by Joule heating. The circular pyramidal kirigami microscanner on a small footprint of 4.5 mm × 4.5 mm was fabricated by microelectromechanical system processes. A large four-step pyramidal actuation was successfully demonstrated, and a large 1.1-mm lens travel range at only 128 mW was achieved.

We report, to the best of our knowledge, the first fully referenced Cr:ZnS optical frequency comb. The comb features few cycle output pulses with 3.25 W average power at 80 MHz repetition rate, spectrum spanning 60 THz in the middle-IR range 1.79–2.86 µm, and a small footprint (0.1 m2), The spectral components used for the measurement of the comb’s carrier envelope offset frequency were obtained directly inside the polycrystalline Cr:ZnS laser medium via intrinsic nonlinear interferometry. Using this scheme we stabilized the offset frequency of the comb with the residual phase noise of 75 mrads.

We designed and fabricated a 4-channel silicon micro-ring modulator (MRM) assembly chip with arrayed grating couplers for space-division-multiplexed optical interconnection. Only 4 channels out of 7 have been utilized with the consideration of popular multi-source-agreements (MSA) compatibility with respect to a 7-core multi-core-fiber (MCF). Experimental modulations at 10, 15, 20 and 25 Gbps have been carried out for all the four channels with clearly opened eye-diagrams which indicates a single-fiber aggregate capacity of 100 Gbps with only one laser input for SDM optical interconnection. The silicon MRM assembly demonstrated in this work is advantageous for practical applications due to its simplified modulation solution (NRZ-OOK) with high capacity (100-Gbps), small footprint (0.45 mm2) and long reach (1 km).

In this manuscript we discuss state of the art hybrid integration techniques and III-V/Si active components with an emphasis on hybrid distributed feedback (DFB) lasers for telecom applications. We review our work on ultra-compact III-V/Si DFB lasers and further describe design considerations and challenges associated with electrically pumped hybrid lasers. We conclude with a perspective on DFB lasers with extremely small footprint, a direction for future research with potential applications to densely-packed optical interconnects.

We present an algorithm for designing high efficiency (∼98%), small-footprint (1.5-4 square vacuum wavelengths) couplers between arbitrary nanophotonic waveguide modes in two dimensions. Our "objective-first" method is computationally fast (15 minutes on a single-core personal computer), requires no trial-and-error, and does not require guessing a good starting design. We demonstrate designs for various coupling problems which suggest that our method allows for the design of any single-mode, linear optical device.