公开(公告)号：US20220091474A1

公开(公告)日：2022-03-24

申请号：US17384861

申请日：2021-07-26

Applicant: Massachusetts Institute of Technology

Inventor： Hyeongrak CHOI ,  Dirk Robert ENGLUND

IPC: G02F1/39 ,  G02F1/35 ,  G02F1/355 ,  G02F1/37

Abstract: It remains a challenge to generate coherent radiation in the spectral range of 0.1-10 THz (“the THz gap”), a band for applications ranging from spectroscopy to security and high-speed wireless communications. Here, we disclose how to produce coherent radiation spanning the THz gap using efficient second-harmonic generation (SHG) in low-loss dielectric structures, starting from an electronic oscillator (EO) that generates coherent radiation at frequencies of about 100 GHz. The EO is coupled to cascaded, hybrid THz-band dielectric cavities that combine (1) extreme field concentration in high-quality-factor resonators with (2) nonlinear materials enhanced by phonon resonances. These cavities convert the input radiation into higher-frequency coherent radiation at conversion efficiencies of >103%/W, making it possible to bridge the THz gap with 1 W of input power. This approach enables efficient, cascaded parametric frequency converters, representing a new generation of light sources extensible into the mid-IR spectrum and beyond.

公开(公告)号：US20190265574A1

公开(公告)日：2019-08-29

申请号：US16284161

申请日：2019-02-25

Applicant: Massachusetts Institute of Technology

Inventor： Scott A. SKIRLO ,  Cheryl Marie SORACE-AGASKAR ,  Marin SOLJACIC ,  Simon VERGHESE ,  Jeffrey S. HERD ,  Paul William JUODAWLKIS ,  Yi YANG ,  Dirk Robert ENGLUND ,  Mihika PRABHU

IPC: G02F1/313 ,  G02F1/295

Abstract: An integrated optical beam steering device includes a planar dielectric lens that collimates beams from different inputs in different directions within the lens plane. It also includes an output coupler, such as a grating or photonic crystal, that guides the collimated beams in different directions out of the lens plane. A switch matrix controls which input port is illuminated and hence the in-plane propagation direction of the collimated beam. And a tunable light source changes the wavelength to control the angle at which the collimated beam leaves the plane of the substrate. The device is very efficient, in part because the input port (and thus in-plane propagation direction) can be changed by actuating only log2 N of the N switches in the switch matrix. It can also be much simpler, smaller, and cheaper because it needs fewer control lines than a conventional optical phased array with the same resolution.