Theory of direct and indirect effect of two-photon absorption on nonlinear optical losses in high power semiconductor lasers

TY - JOUR

T1 - Theory of direct and indirect effect of two-photon absorption on nonlinear optical losses in high power semiconductor lasers

AU - Avrutin, E. A.

AU - Ryvkin, B. S.

N1 - © 2016 IOP Publishing Ltd. This is an author-produced version of the published paper. Uploaded in accordance with the publisher’s self-archiving policy. Further copying may not be permitted; contact the publisher for details

PY - 2017/1/1

Y1 - 2017/1/1

N2 - The effect of the transverse laser structure on two-photon absorption (TPA) related effects in high-power diode lasers is analysed theoretically. The direct effect of TPA is found to depend significantly on the transverse waveguide structure, and predicted to be weaker in broad and asymmetric waveguide designs. The indirect effect of TPA, via carrier generation in the waveguide and free-carrier absorption, is analysed for the case of a symmetric laser waveguide and shown to be strongly dependent on the active layer position. With the active layer near the mode peak, the indirect effect is weaker than the direct effect due to the population of TPA-created carriers being efficiently depleted by their diffusion and capture into the active layer, whereas for the active layer position strongly shifted towards the p-cladding, the indirect effect can become the dominant power limitation at very high currents. It is shown that for optimizing a laser design for pulsed high power operation, both TPA related effects and the inhomogeneous carrier accumulation in the waveguide caused by diffusive current need to be taken into account.

AB - The effect of the transverse laser structure on two-photon absorption (TPA) related effects in high-power diode lasers is analysed theoretically. The direct effect of TPA is found to depend significantly on the transverse waveguide structure, and predicted to be weaker in broad and asymmetric waveguide designs. The indirect effect of TPA, via carrier generation in the waveguide and free-carrier absorption, is analysed for the case of a symmetric laser waveguide and shown to be strongly dependent on the active layer position. With the active layer near the mode peak, the indirect effect is weaker than the direct effect due to the population of TPA-created carriers being efficiently depleted by their diffusion and capture into the active layer, whereas for the active layer position strongly shifted towards the p-cladding, the indirect effect can become the dominant power limitation at very high currents. It is shown that for optimizing a laser design for pulsed high power operation, both TPA related effects and the inhomogeneous carrier accumulation in the waveguide caused by diffusive current need to be taken into account.

KW - high power lasers

KW - semiconductor lasers

KW - two-photon absorption

UR - http://www.scopus.com/inward/record.url?scp=85007173862&partnerID=8YFLogxK

U2 - 10.1088/1361-6641/32/1/015004

DO - 10.1088/1361-6641/32/1/015004

M3 - Article

AN - SCOPUS:85007173862

VL - 32

JO - Semiconductor science and technology

JF - Semiconductor science and technology

SN - 0268-1242

IS - 1

M1 - 015004

ER -