An appreciation of usability of the finite element method for the thermal analysis of stripe-geometry diode lasers

Abstract

An appreciation of usability of the finite element technique for the thermal analysis of stripe-geometry diode lasers is carried out in the present work. Thye technique appears to be very exact and surprisingly speed using even a standard IBM PC/AT microcomputer.As an example, a finite-element thermal analysis of the diffused-stripe doubleheterostructure GaAs/(AIGa)As diode laser is carried out. A system of isotherms obtained for the above laser enables us to discuss the heat spreading process within its structure and to compare relative contributions of all heat sources.An operation of diode lasers (DLS) strongly depends on their thermal properties because all electrical and optical processes taking place inside a DL crystal are temperature-dependent. Consequently all DL operation characteristics are sensitive to a temperature distribution within and around a DL active area. Therefore thermal properties of diode lasers are of prime importance.Up to now experimental methods determining temperature profiles within the DL crystal with a required space resolution and a necessary temperature exactness have not been found. Therefore theoretical thermal modelling of diode lasers remains the most useful tool for such an application.Most of thermal models [1-7] of stripe-geometry diode lasers are based on the classical semi-analytical thermal analysis of the diffused-stripe diode lasers reported by Joyce and Dixon [8]. There are also known fully analytical thermal DL models for a steady state cw operation [9, 10], a transient-state pulse operation [11] and self-cooling of the DL crystal between the current pulses [12]. John grdey & Sons, Limi~ ChichesterKiad6, Budapest

Thermomechanical issues of high power laser diode catastrophic optical damage

“…Several studies on the temperature distribution on DH lasers and on the evaluation of their thermal resistances followed. The problems were tackled either via analytical resolution [42], finite difference (FD) methods [43,44] or finite element method (FEM) [45,46]. Most of these works merely considered the existence of a uniformly distributed heat source in the active region [42][43][44] which was associated with the non-radiative recombination of excess carriers.…”

Mathematical Models of Heat Flow in Edge-Emitting Semiconductor Lasers

“…In recent years, numerical methods seem to prevail. Pioneering works using Finite Element Method (FEM) in the context of thermal investigations of edge-emitting lasers have been described by Sarzała & Nakwaski (1990;. Broader discussion of analytical vs. numerical methods is presented in 8.3.…”

Microthermography of diode lasers: The impact of light propagation on image formation

“…For the heat sources we took into account the active-area heating by nonradiative recombination, absorption of radiation within this area, absorption of energy transferred radiatively from the active area, generation of heat via Ohmic losses at the contacts, and Joule heating. 12,13 The heat-generation rate of the active region is extracted from experimental current-voltage and currentoutput power characteristics. The bottom surface of the C mount linked to the Peltier cooler is assumed to be fixed at the ambient temperature, whereas the other surfaces of the structure are considered to be thermally isolated.…”