US 7,406,267 B2
	Method and apparatus for transmitting a signal using thermal chirp management of a directly modulated transmitter
Daniel Mahgerefteh, Los Angeles, Calif. (US); Roeland Nuyts, Utrecht (Netherlands); Yasuhiro Matsui, Lawrence, Mass. (US); Parviz Tayebati, Weston, Mass. (US); Bart Johnson, North Andover, Mass. (US); Duncan Walker, Somerville, Mass. (US); and Xueyan Zheng, Culver City, Calif. (US)
Assigned to Finisar Corporation, Sunnyvale, Calif. (US)
Filed on Sep. 02, 2004, as Appl. No. 10/933,081.
Application 10/933081 is a continuation in part of application No. 10/289944, filed on Nov. 06, 2002, granted, now 6,963,685.
Claims priority of provisional application 60/557538, filed on Mar. 30, 2004.
Claims priority of provisional application 60/530479, filed on Dec. 17, 2003.
Claims priority of provisional application 60/500540, filed on Sep. 05, 2003.
Prior Publication US 2005/0111852 A1, May 26, 2005
Int. Cl. H04B 10/04 (2006.01)

U.S. Cl. 398—201  [398/185; 398/186; 398/187]

47 Claims

1. A fiber optic transmitter comprising a digital driver configured to generate a digital base signal transitioning between high and low signal levels, the digital driver further configured to maintain a crossing point of the digital base signal at an offset signal level substantially different from a middle signal level located at 50% of a distance between the high and low signal levels; an optical source adapted to receive the digital base signal and produce a frequency modulated optical signal, the offset signal level being offset from the middle signal by an amount effective to reduce thermal chirp in the frequency modulated optical signal; and an optical spectrum reshaper adapted to convert the frequency modulated optical signal to an amplitude modulated optical signal.