Threshold conditions for a random laser mode

Stimulated emission in Nd0.5La0.5Al3(BO3)4 ceramic random laser was studied at different diameters of the pumped spot d. The developed heuristic model adequately describes the dependence of threshold pumping energy density versus d at d greater or equal to 150 micrometer. At small pumping beam diameter (less than 100 micrometer), very bright and strongly localized emission spot was observed in the center of the pumped area. The spectrum of the bright-spot emission appeared to be similar to that of 'continuum wave' light sources.

[1]  R M Balachandran,et al.  Photonic textile fibers. , 1996, Applied optics.

[2]  Jiang,et al.  Time dependent theory for random lasers , 2000, Physical review letters.

[3]  S. LaRochelle,et al.  Long range interrogation of laser paints for identification applications , 1997, CLEO '97., Summaries of Papers Presented at the Conference on Lasers and Electro-Optics.

[4]  Mikhail A. Noginov,et al.  Threshold and slope efficiency of Nd0.5La0.5Al3(BO3)4 ceramic random laser: effect of the pumped spot size , 2002 .

[5]  H. Caulfield,et al.  Stimulated Emission without Cavity in Powders and Single Crystals of Nd Doped Materials , 1996 .

[6]  V. N. Lichmanova,et al.  Degree of coherence and dimensions of the generation region of powder lasers , 1998 .

[7]  Robert P. H. Chang,et al.  Microlaser made of disordered media , 2000 .

[8]  Qiming Li,et al.  Mode distribution in coherently amplifying random media , 2001 .

[9]  Robert P. H. Chang,et al.  Investigation of random lasers with resonant feedback , 2001 .

[10]  V. S. Letokhov,et al.  Stimulated Emission of an Ensemble of Scattering Particles with Negative Absorption , 1967 .

[11]  Arnold Migus,et al.  Generation of spatially incoherent short pulses in laser-pumped neodymium stoichiometric crystals and powders , 1993 .

[12]  N. Lawandy,et al.  Laser action in strongly scattering media , 1994, Nature.

[13]  Ch. M. Briskina,et al.  Stimulated emission kinetics of neodymium powder lasers , 1990 .

[14]  G. G. Stokes.  "J." , 1890, The New Yale Book of Quotations.

[15]  Hui Cao,et al.  Random Lasers with Coherent Feedback , 2001 .

[16]  H. J. Caulfield,et al.  Short-pulsed stimulated emission in the powders of NdAl 3 (BO 3 ) 4 , NdSc 3 (BO 3 ) 4 , and Nd:Sr 5 (PO 4 ) 3 F laser crystals , 1996 .

[17]  Stephen C. Rand,et al.  Laser action in strongly scattering rare-earth-metal-doped dielectric nanophosphors , 2001 .

[18]  Hall,et al.  Direct link between microwave and optical frequencies with a 300 THz femtosecond laser comb , 2000, Physical review letters.

[19]  Brian Joseph Mangan,et al.  Photonic Crystal Fibers: New Solutions in Fiber Optics , 2002 .

[20]  Hui Cao,et al.  Dynamic response and relaxation oscillations in random lasers , 2002 .

[21]  Vladilen S. Letokhov,et al.  Generation of Light by a Scattering Medium with Negative Resonance Absorption , 1968 .

[22]  S. T. Durmanov,et al.  Binary rare-earth scandium borates for diode-pumped lasers , 2001 .

[23]  Patrick Sebbah,et al.  Selective Excitation of Localized Modes in Active Random Media , 2001 .

[24]  H. J. Caulfield,et al.  Study of the pumping regimes in Ti-sapphire and Nd0.5La0.5Al3(BO3)4 powders , 1998 .

[25]  Z. V. Vardeny,et al.  Analysis of Random Lasers in Thin Films of π-Conjugated Polymers , 2001 .