16 years ago
I want to modulate a Red and Green laser pointer (laser diode) with audio
sweep signal 1-10KHz square wave with adjustable duty cycle.
For the modulation I'm planning to use a simple transistor circuit where the
base of the transistor will be conneced to a signal generator and the laser
pointer will be connected to the collector of the transistor. The transistor
will be used to switch on/off the laser diode.
How to sweep the modulation signal and rotate the laser pointer
Signal generator will sweep the frequency from 1KHz to 10KHz in 1second.
During this 1 second period laser pointer will be physically rotated from 0
degree to 180 degree (From Left to Right). Then signal generator will sweep
the signal from 10KHz down to 1KHz and laser pointer will be rotated from
180 degree to 0 degree (From Right to Left).
Laser receiver sensor
There will be a receiver/sensor on an arbitrary position at a distance of
100meters (or more). When the laser light hits the sensor, I want to detect
the laser signal and demodulate the received signal. The frequency of the
demodulated signal will indicate the angle of the receiver/sensor with
repect to the laser pointer.
1.) Can you advise a good way of modulating the laser pointer?
2.) What can I use as receiver sensor which can operate even in daylight?
3.) Can you advise a good way of demodulating/decoding the received signal?
4.) Would it make any difference if I use either Red or Green laser