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JOURNALS // Kvantovaya Elektronika // Archive

Kvantovaya Elektronika, 1971 Number 3, Pages 120–121 (Mi qe3110)

This article is cited in 2 papers

Brief Communications

Optimal thickness of the active layer in a heterojunction laser

P. G. Eliseev


Abstract: Optimization of a symmetrical heterostructure is considered and the minimal value of the threshold current of a heterojunction laser at 300°K is calculated. It is shown that in the case of linear or superlinear (but weaker than quadratic) dependence of the optical gain on the current, the optimal thickness of the active layer d0 can be deduced from a waveguide model. If the gain-current characteristic is linear, it is shown that d0 = 0.27 μ when the relative change in the permittivity at the boundary of the active layer is δ ε/ε = 0.04 (a change of this magnitude is observed in GaAs–AlxGa1–xAs heterojunctions). If the gain-current characteristic is superlinear, optimization of the dielectric waveguide leads to d0 → 0. Calculations of this type must make allowance for the upper limit of the rise of the gain. Calculations performed taking all these points into account show that the minimal values of the threshold current density are of the order of 1 kA/cm2 for a heterojunction laser operating at 300°K in an unloaded Fabry–Perot resonator.

UDC: 543.42:621.378.325

PACS: 42.55.Px, 42.60.Lh, 42.60.Da, 42.79.Gn

Received: 18.01.1971


 English version:
Soviet Journal of Quantum Electronics, 1971, 1:3, 304–305


© Steklov Math. Inst. of RAS, 2025