The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 10, 2018
Filed:
Jan. 30, 2017
Erman Timurdogan, Cambridge, MA (US);
Michael R. Watts, Hingham, MA (US);
Zhan Su, Cambridge, MA (US);
Ehsan Shah Hosseini, Boston, MA (US);
Jie Sun, Cambridge, MA (US);
Erman Timurdogan, Cambridge, MA (US);
Michael R. Watts, Hingham, MA (US);
Zhan Su, Cambridge, MA (US);
Ehsan Shah Hosseini, Boston, MA (US);
Jie Sun, Cambridge, MA (US);
Massachusetts Institute of Technology, Cambridge, MA (US);
Abstract
A photodetector includes a germanium layer evanescently coupled to a ring resonator. The ring resonator increases the interaction length between light guided by the ring resonator and the germanium layer without increasing the size of the photodetector, thereby keeping the photodetector's dark current at a low level. The germanium layer absorbs the guided light and converts the absorbed light into electrical signals for detection. The increased interaction length in the resonator allows efficient transfer of light from the resonator to the germanium layer via evanescently coupling. In addition, the internal and external quality factors (Q) of the ring resonator can be matched to achieve (nearly) full absorption of light in the germanium with high quantum efficiency.