I would like to find out what is thew difference between a modulating
laser diode and a continuous wave laser diode. What kind of
applications can be used for each type of laser diode?

Briefly, not to Hijack a possible researcher?s $15.

Modulation of a laser diode is not intrinsically a function of the
laser but how it is used. If one merely wishes laser illumination such
as in a CD, the signal is not modulation except for current
stabilising. If however the application is to transmit information in
fibre optics, the signal is modulated.

Diodes are however designed for specific application so generally the
characteristics are tailored to be appropriate for continuous wave or
modulation. Design parameters include speed of response and power
handling. Package is also important such that they may be integrated
into standard fittings.

Best

hello
in case of the modulating diodes the laser light is modulated and then
transmitted to the detector. for eg:-communication between a pic
microcontroller to the PC i.e., we are transmitting the  data from the
PC and it is modulated by the laser and the it is given to the
detector and then it is given to the PIC which can display the
transmitted data on the LCD panel or act according to the transmitted
command.This is just a modulating laser.normally used for the
communication.
as posted by guzzi in cd-writing / DVD-writing.... reading......
Holographic data manipulations.....



In case of the continous laser the diode emitts a continous light.This
can be used in the application like count number of person who entered
the room i.e., the low intensity laser light will be falling on the
detector, when a person enters the room the person cuts the light
which disturbs the detector i.e., it generates a pulse and hence we
can identify that some body has entered the room and also it can be
used to count the number of person who entered.
Another application that can be used is for tracking the
objects,guiding objects etc.....
and also used in the medical applications also in cutting of metals etc...