Semiconductor optical gain

About: Semiconductor optical gain is a research topic. Over the lifetime, 5997 publications have been published within this topic receiving 96505 citations.

Optical gain, loss, and transparency current in high performance mid-infrared interband cascade lasers

Abstract: The net modal gain, optical loss, and transparency current of high-performance, narrow ridge waveguide interband cascade (IC) lasers have been measured using the Hakki–Paoli technique in the temperature range from T=78 to 270 K. In this temperature range, the optical loss of IC lasers increases from αw≈17 cm−1 at T=78 K to αw≈35 at T=270 K, the transparency current density rises from Itr=10 to 330 A∕cm2, and the differential gain decreases from gd≈2.2 cm∕A to gd≈0.06 cm∕A with a characteristic temperature of T0=130 K. The implications of these observed characteristics for IC lasers are discussed.

Dynamics of a globally coupled laser model.

Abstract: We study analytically and numerically a model of N identical globally coupled lasers. We extend the discussion of the linear stability, presented in a recent paper [Silber et al., J. Opt. Soc. Am. B 10, 1121 (1993)] for general splay states. For semiconductor lasers, we find that the splay state is neutrally stable only for a narrow range \ensuremath{\Delta}, a parameter characterizing the splay state. We draw the phase diagram for semiconductor lasers using characteristic parameter values. We then analyze the model numerically, both for semiconductor lasers and for solid-state lasers. We also investigate the diffusion of the splay state on the solution branch in the presence of a noise term. Finally, we discuss the linear stability of the periodic two-cluster state found for semiconductor lasers.

Saturation of light – current characteristics of high-power lasers (λ = 1.0 – 1.1 mm) in pulsed regime

Abstract: Semiconductor lasers based on MOVPE-grown asymmetric separate-confinement heterostructures with a broadened waveguide and emitting in the wavelength range 1.0 – 1.1 μm are studied. It is found that the intensity of spontaneous emission from the active region increases with increasing pump current above the lasing threshold and that this is caused by a growth in the concentration of charge carriers in the active region due to the modal gain enhancement needed to compensate for the growing internal optical loss at high pulsed pump currents. It is shown that the increase in the internal optical loss with increasing pulsed pump current is one of the main reasons for saturation of the light – current characteristics of high-power semiconductor lasers.

The inception of charge-coupled devices

Abstract: I T WOULD seem that the authors of the papers in this special issue have a very heavy responsibility. Much has been written about the mental processes that lead to innovation but this is one of the rare times that a group of people who themselves have participated in the act of innovati,on have been asked to shed some light on the factors which contributed to the generation of a new concept. It is not difficult to document the apparently important features; they have been told many times before. Indeed the telling and retelling with embellishments of “the day that etc.” gradually takes on a ring of authenticity that eventually becomes fact in itself. On this occasion, however, we shall try to analyze once again just exactly what did transpire, with the full understanding that with all the best effort at objectivity, it may still not be an accurate account of the subtle interplay between people that certainly played a most important role in our own work. The charge-coupled device concept is one that is basically a structure that called upon existing technology and was stimulated by the analogous work that preceded it in magnetic bubbles. All the ingredients necessary for the innovation were found within Bell Laboratories. The now well-known work at the Philips Eindhoven Laboratory by Sangster [l] and his colleagues on the Bucket Brigade was unknown to us. The importance of the Bucket Brigade as a member of the family of charge transfer devices is well recognized, and we want at this point to recognize the important contribution to device technology that has been made by the work a t Philips. In :late 1969, the device area of Bell Laboratories was strongly oriented towards innovation and exploratory development of new devices. Strong efforts were being directed towards such fields as IMPATT diodes, GaAs lasers, nonlinear optics, solid-state lasers, holography, Gunn diodes, magnetic bubbles, and the silicon diode array came.ra tube. Of particular interest was the work on magnetic bubbles. It was apparent that a radically new approach to signal processing was being brought into existence. Those of us who were working on semiconductor integrated circuits looked at the work in magnetic bubbles with some awe. In the magnetic bubbles it seemed that a new class of devices was in the offing in which there was a very natural and appealing way of storing and manipulating bits with a one-to-one correspondence to the digital format. It could. be argued that semiconductor integrated circuits, important as they were, had not yet broken away from the circuit concepts that had evolved through the use of dis-

Optical power of semiconductor lasers with a low-dimensional active region

Abstract: A comprehensive analytical model for the operating characteristics of semiconductor lasers with a low-dimensional active region is developed. Particular emphasis is given to the effect of capture delay of both electrons and holes from a bulk optical confinement region into a quantum-confined active region and an extended set of rate equations is used. We derive a closed-form expression for the internal quantum efficiency as an explicit function of the injection current and parameters of a laser structure. Due to either electron or hole capture delay, the internal efficiency decreases with increasing injection current above the lasing threshold thus causing sublinearity of the light-current characteristic of a laser.