Laser Diode (650nm)
- RoHS (Restriction of Hazardous Substances) Compliant
- Quality level is high
- Cost is economical
- Wavelength from 635 nm to 660 nm
- Rise and fall time is 0.5ns
- Package available:- TO-18(dia. 5.6mm), TO-5 (dia. 9 mm)
- Operating Temperature:- -10～+40 ℃
- Storage Temperature:- -15～+85 ℃
- Output power (Po):- 5 mW
- Normal and maximum operating voltage is 2.2 and 2.7 respectively
- Threshold current in minimum, normal and maximum condition are 15, 20 and 30mA
- Operating current is 65 to 80mA
- Beam Angle deviation:-
- For both parallel and perpendicular condition its between -3 to 3 degree
- Beam divergence:-
- For parallel condition it’s between 8 to 12 degree
- For perpendicular condition it’s between 23 to 32 degree
1.Temperature Effect on Operation of Laser Diode
This graph is between Optical output power v/s forward current. It’s clear from the graph that laser output will only be visible if obtained above the threshold value of the laser diode. Before the threshold value the output of the laser diode is zero. After the threshold value the output of laser diode increase with slightly increase in forward voltage. The effect of temperature in the operation of Laser Diode is shown in graph below:
2.Laser Beam Divergence in parallel and perpendicular plane
3.Forward voltage v/s Forward current
4.Output Power v/s Forward Current
If the direction of moving current is forward and the output is continuously increasing, after the kink level the laser face a sudden breakdown which is the COD (Catastrophic Optical Damage) level. At this level due to high optical density the crystal at the face of diode melts. At the time of manufacturing of Red lasers a special care is taken to avoid surge like static electricity and increase in current, because in red laser the oscillation is occur with the low power of 2 to 3 mW even after the breakdown. As the element is damaged the laser gets damaged or not able to work.
How to use a Laser Diode?
If we want to operate a Laser diode then we must have laser diode driver circuit. As it helps in limiting current then supply it to laser diode. A laser diode can only work properly with the help of this circuit, if we directly connect it to the supply, because of having more current it will damage and if the value of current is low then the laser diode will not operate. Laser Diode driver circuit helps in providing a correct value of current to operate the laser diode. For making a laser diode driver circuit we need a few no. of components like resistor, capacitor and a voltage regulator IC.
The first capacitor in the circuit filter the High-frequency noise from the DC supply. The second capacitor works as power load balancer used to filter the fluctuating signals of output voltage. And a voltage regulator IC is used to provide a fix output voltage and we can adjust the output voltage by changing the value of resistor. You can use a potentiometer instead of resistor (R2) to adjust the intensity of laser light.
- Industrial applications: Engraving, cutting, scribing, drilling, welding, etc.
- Medical applications: to remove unwanted tissues, diagnostics of cancer cells using fluorescence, dental medication.
- Military application
- Data storage