LASER DIODE STRIP Russian patent published in 2001 - IPC

FIELD: semiconductor lasers; fiber-optic communications, medicine, material treatment. SUBSTANCE: laser diode strip whose external end is covered with antireflective coating and rear blind end, with highly reflective coating has laser diodes, cylindrical microlens, and flat external mirror; transversely directed multimode wide-aperture (S > 50 mcm) laser diodes are used in strip, their mode of operation being changed from inherent multimode to transversely single-mode operation in external resonator where laser diodes are synchronized due to diffraction transmission of radiation during reflection from external mirror. Entire radiation energy is concentrated in central peak by using ability of Gaussian beam to change curvature of its wavefront and its cross-sectional dimensions when propagating in free space and also ability of positive lens to reduce constriction in rear focal plane provided distance between lens and original constriction measuring W_o is much longer than both focal distance of lens and Rayleigh length parameter πW20

/λ, where λ is radiation wavelength; as a result, angular size of transformed constriction is smaller than angular direction to first diffraction peak which reduces intensity of the latter as well as of higher-order peaks due to interference of laser-diode fields causing concentration of entire radiation energy in single (central) peak. EFFECT: provision for concentrating entire radiation energy in single peak with diffraction-limited divergence of diode strip in focal plane of lens. 5 dwg