公开(公告)号：US20200284910A1

公开(公告)日：2020-09-10

申请号：US16798538

申请日：2020-02-24

申请人： Massachusetts Institute of Technology

发明人： Ami YAACOBI ,  Michael R. WATTS

IPC分类号： G01S17/36 ,  G01S7/4915 ,  G01S17/931 ,  G01S7/499

摘要： An optical phased array formed of a large number of nanophotonic antenna elements can be used to project complex images into the far field. These nanophotonic phased arrays, including the nanophotonic antenna elements and waveguides, can be formed on a single chip of silicon using complementary metal-oxide-semiconductor (CMOS) processes. Directional couplers evanescently couple light from the waveguides to the nanophotonic antenna elements, which emit the light as beams with phases and amplitudes selected so that the emitted beams interfere in the far field to produce the desired pattern. In some cases, each antenna in the phased array may be optically coupled to a corresponding variable delay line, such as a thermo-optically tuned waveguide or a liquid-filled cell, which can be used to vary the phase of the antenna's output (and the resulting far-field interference pattern).

公开(公告)号：US20180269653A1

公开(公告)日：2018-09-20

申请号：US15592905

申请日：2017-05-11

申请人： Massachusetts Institute of Technology

发明人： Katia SHTYRKOVA ,  Erich P. IPPEN ,  Franz X. KAERTNER ,  Patrick T. CALLAHAN ,  Michael R. WATTS

IPC分类号： H01S5/065 ,  H01S5/06 ,  H01S5/026 ,  H01S5/062 ,  H01S5/10 ,  H01S5/04 ,  H01S5/042 ,  H01S5/024 ,  H01S5/0625

CPC分类号： H01S5/0657 ,  H01S3/0637 ,  H01S3/08054 ,  H01S3/082 ,  H01S3/1112 ,  H01S3/1616 ,  H01S3/1636 ,  H01S5/02453 ,  H01S5/026 ,  H01S5/041 ,  H01S5/042 ,  H01S5/0604 ,  H01S5/06236 ,  H01S5/06246 ,  H01S5/06251 ,  H01S5/0651 ,  H01S5/1007

摘要： An artificial saturable absorber uses additive pulse mode-locking to enable pulse operation of an on-chip laser operation. Four different artificial saturable absorbers are disclosed. The first includes an integrated coupler, two arms each containing some implementation of the end-reflector, and a phase bias element in one arm. The second includes an integrated directional coupler, two integrated waveguide arms, and another integrated coupler as an output. The third includes an integrated birefringent element, integrated birefringent-free waveguide, and integrated polarizer. And the fourth includes a multimode waveguide that allows for different modes to propagate in such a way that the difference in the spatial distribution of intensity causes a nonlinear phase difference between the modes. These are just some examples of an on-chip fully integrated artificial saturable absorber with instantaneous recovery time that allow for generation of sub-femtosecond optical pulses at high repetition rates using passive mode-locking.