laser diode problem the beam width using the knife edge

[harryd]

laser diode problem

i need to find out the beam width using the knife edge technique , so i need find out what type of detector should be used in the experiment and why ?

 

[karesz]

laser diode problem

Hi,
Your detector must have sensitivity at the desired wavelength & speed for the pulsing, than applicable packaging...
K.

 

[harryd]

Re: laser diode problem

would a simple photo diode do the trick ?

 

[karesz]

laser diode problem

Whats your wavelength and power pls?

 

[harryd]

well i am using a simple laser point so thats about 630 nm and 2mw i think . anyways, i think i will just use a simple photodiode.

 

[karesz]

Or you can take in these case a simple Photoresistor too...
I think is the indication some easyer
K.

 

[harryd]

ok i am using a transistor, i need a circuit for the transistor to detect the a red light from a laser pointer. i also need to know how to calculate the resistance required for the circuit etc...


thanks in advance

 

[karesz]

Hi,
Maybe their helps;
www.tpub.com/neets/book7/26g.htm
Light Detector Circuits:
www.discovercircuits.com/DJ-Circuits/light-det-circuits.htm
www.faqs.org/patents/app/20090108176
www.evilmadscientist.com/article.php/nightlight
Photodetector circuit with BP103 Phototransistor Siemens: www.free-circuit.com/photodetector-circuit-with-bp103-phototransistor-siemens/
Photo Sensor Application Note: www.marktechopto.com/Engineering-Services/photo-sensor-application-note.cfm
K.