Threshold characteristics of InGaAsP/InP multiple quantum well lasers

Abstract

A theoretical analysis and computer simulation of the threshold current density j th and characteristic temperature T 0 of multiple quantum well lasers (MQWLs) are presented. Together with the spontaneous radiative recombination, the Auger recombination and the lateral diffusive leakage of carriers from the active region are included into the model. A first-principle calculation of the Auger recombination current is performed. It is shown that the lateral diffusive leakage current is controlled by the radiative and Auger currents. When calculating the carrier densities, the electrons in the barrier regions are properly taken into account. Redistribution of electrons over the active region is shown to increase the threshold current considerably. The dependences of j th and T 0 on temperature, number of QWs, cavity length and lateral size are discussed in detail. The effect of lattice and carrier heating on j th and T 0 is investigated and shown to be essential at high temperature.

Light-current characteristic of a quantum well laser with asymmetric barrier layers

“…As seen from Eqs. (10) and (12), the higher v capt, 0 , the slower is the increase of n OCL and j OCL with increasing j. In the limiting case of v capt, 0 !…”

“…In the conventional design of injection lasers, there is always bipolar (i.e., both electron and hole) population, and hence electron-hole recombination, not only in the active region [quantum wells (QWs), quantum wires, or quantum dots (QDs)] but also in the optical confinement layer (OCL). [1][2][3][4][5][6][7][8][9][10] Parasitic recombination outside the active region presents a major cause for the temperature-dependence of the threshold current in conventional semiconductor lasers. It also leads to sublinearity of the light-current characteristic (LCC) in such lasers.…”

Intraband light absorption by holes in InGaAsP/InP quantum wells

“…Experimental results [7,8] show that the laser radiation intraband absorption coefficient is substantially higher than predicted by the theory [9]. One of the candidates for explaining these results is the process radiation intraband absorption process by holes with the transition to the spin-split (so) zone.…”

Analytical model for threshold‐base current of a transistor laser with multiple quantum wells in the base

“…We assumed that only the first subbands (both in the conduction and valence bands) are involved in the optical transitions in narrow QWs [16]. For the transitions from a quantised energy level in the conduction band to that in the valence band in a QW, the material gain g(h − v) reduced to one QW can be written as [16] (see (11)) where h − v is the photon energy; d is the QW width; a = e 2 /4p1 0 h − c 1/137; ε is the relative permittivity of the optical confinement layer (OCL); m 0 is the free electron mass; M = m hh /m c , m c and m hh are the electron and heavy-hole effective masses; E g is the band gap and Δ 0 is the energy of the spin-orbit splitting in the QW material; E CV is the energy of the optical transition (photon energy); E C,str and E V,str are the quantised energy levels under strain of an electron and a hole in the conduction and valence bands, respectively, measured from the band edges (Fig.…”

“…For wide QWs it is a good approximation to take I CV = 1 [16]. For the case of narrow rectangular QWs, the following equation has been derived for I CV [16] and has been used in our work (see (13)) where ΔE C and ΔE V are the conduction band and valence band offsets at QW -OCL heteroboundary (Fig.…”