公开(公告)号：US20180269653A1

公开(公告)日：2018-09-20

申请号：US15592905

申请日：2017-05-11

Applicant: Massachusetts Institute of Technology

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

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

CPC classification number: 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

Abstract: 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.

公开(公告)号：US20170269455A1

公开(公告)日：2017-09-21

申请号：US15463717

申请日：2017-03-20

Applicant: Deutsches Elektronen-Synchrotron DESY ,  Massachusetts Institute of Technology (MIT)

Inventor： Franz X. KAERTNER ,  Damian N. BARRE ,  Michael HEMMER ,  Giovanni CIRMI ,  Oliver D. MUECKE ,  Giulio Maria ROSSI ,  Arya FALLAHI ,  Nicholas H. MATLIS ,  Luis E. ZAPATA ,  Koustuban RAVI ,  Fabian REICHERT

IPC: G02F1/355 ,  G02F1/35

CPC classification number: G02F1/3551 ,  G02F1/3501 ,  G02F1/353 ,  G02F1/3534 ,  G02F1/3544 ,  G02F1/3558 ,  G02F1/39 ,  G02F2001/3548 ,  G02F2001/392 ,  G02F2201/16 ,  G02F2203/13 ,  G02F2203/56

Abstract: A method of generating THz radiation includes the steps of generating optical input radiation with an input radiation source device (10), irradiating a first conversion crystal device (30) with the optical input radiation, wherein the first conversion crystal device (30) is arranged in a single pass configuration, and generating the THz radiation having a THz frequency in the first conversion crystal device (30) in response to the optical input radiation by an optical-to-THz-conversion process, wherein a multi-line frequency spectrum is provided by the optical input radiation in the first conversion crystal device (30), and the optical-to-THz-conversion process includes cascaded difference frequency generation using the multi-line frequency spectrum. Furthermore, a THz source apparatus being configured for generating THz radiation and applications thereof are described.