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:
Dec. 25, 2001
Filed:
Dec. 14, 1999
Masataka Nakazawa, Mito, JP;
Eiji Yoshida, Yokosuka, JP;
Nippon Telegraph and Telephone Corporation, Tokyo, JP;
Abstract
An ultra-stable microwave output with less jitter than a prior art atomic oscillator is obtained and an ultra-short optical pulse train is generated with a repetition frequency stabilized at the same level as a time standard. The repetition frequency of a regeneratively mode-locked laser pulse oscillator with a superior low-jitter characteristic is locked directly to a resonance frequency of various atoms. The oscillator provides the means for detecting the frequency difference between the clock signal frequency and a predetermined atomic resonance frequency and outputting it as an error signal, a cavity length tuning device for varying the length of a laser cavity so that the clock signal frequency and the predetermined resonance frequency coincide, and a device for negatively feeding back the error signal output from the frequency difference detection device to the cavity length tuning device. This allows the generation of an optical pulse train (optical output) and a clock signal (microwave output) of a repetition frequency stabilized to the predetermined atomic resonance frequency.