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.

Date of Patent:
Dec. 12, 2000

Filed:

Aug. 04, 1998
Applicant:
Inventors:

Gerard A Mourou, Ann Arbor, MI (US);

Joo-Hiuk Son, Albany, CA (US);

Joungho Kim, Seoul, KR;

Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H01L / ; H01L / ; H01L / ; G01R / ;
U.S. Cl.
CPC ...
2502141 ; 257 21 ; 257431 ; 324 96 ;
Abstract

A photoconductive method or apparatus for measuring high frequency signals using a relatively inexpensive photoconductive material with a relatively long duration or recombination time. The photoconductive method or apparatus utilizes a photoconductive element of photoconductive material such that the duration or recombination time of the photoconductive material is longer than the pulse width of the signal to be measured. As such, the photoconductive element produces a step function response to the signal to be measured rather than a rectangular response with respect to the signal to be measured. The photoconductive element avoids the need to sacrifice measurement sensitivity by introducing defects in the photoconductive material to shorten the recombination time or duration. The measurement bandwidth of the photoconductive element is not limited by the recombination time of the photoconductive material which is mostly dominated by the carrier lifetime. The measurement bandwidth for the photoconductive element is limited by the pulse width of the optical signal driving the photoconductive element which can be very short duration thereby providing improved resolution. As such, the photoconductive element can comprise a cheaper photoconductive material which has a longer duration or recombination time but with a higher sensitivity and improved measurement resolution.


Find Patent Forward Citations

Loading…