MULTI-EMITTER ARRAY LASERS
Original Publication Date: 1985-Aug-31
Included in the Prior Art Database: 2004-Apr-04
Xerox Disclosure Journal
With 10 emitter array lasers, the far-field radiation pattern often consists of one or two phase-locked radiation lobes near laser threshold. At threshold, this is generally due to emission from five to eight of the lasers. Never do the outer two emitters near the edge of the array reach threshold at the same current as do the centrally located lasers. As the laser power is increased above threshold, these outer edge lasers begin to lase with often a different wavelength and phase relative to the centrally located lasers. This action begins to distort the far-field radiation pattern, and can even cause a new set of phase-locked emitters to lase across the entire width of the array. See, for example, the article of D.R. Scifres et a1 entitled, "Near and Far Field Patterns of Phased Locked Semiconductor Laser Arrays", Applied Physics Letters, Volume 42, No. 6, pp. 495-497, March 15, 1983. This is undesirable behavior if the laser beam is to be collimated or focused.