Rami Arieli: "The
Laser Adventure" Chapter 6.3 Diode lasers Page 12.
Dependence of diode laser parameters
on temperature
One of the problems of diode lasers is the increase
in threshold current for lasing with the increase in temperature (µ
T3).
Operating laser diodes at low temperatures require
lower currents.
As current flows through the diode, heat is created.
If the heat dissipation is not adequate, the
diode temperature increases, and the required threshold current increases
as well.
Changes in temperature cause changes
in the wavelength emitted from the diode laser. The change
in wavelength with temperature is illustrated in figure 6.27. It is composed
of 2 parts:
-
A gradual increase in wavelength with increased temperature,
until:
-
A jump to another longitudinal mode occurs.
This jump is called "Mode Hope"
Figure 6.27: change in the diode laser wavelength
with temperature.
Because of temperature variations, special structures need to
be designed for the diode lasers to achieve high power of continuous laser
radiation.