User:Pranav Rathi/Notebook/OT/2010/10/31/Laser Shutter .1

I have constructed a cost-effective mechanical laser shutter system for our 1064 IR-laser. System contains a mechanical shutter, a control box and a power supply. There are many shutter systems available commercially; mechanical, semi-mechanical, electromagnetic and optical. Most of the systems are expensive and above $1000. These systems are fast (msecs to micro secs) and precise. In our case we needed a shutter which is precise and cost effective but not that fast. Some of the specifications of the system:

• Type mechanical with electronic control. Can also be controlled by a micro controller.
• Aperture 10mm.
• Open time 1.5 second, .3 second over the beam waist.
• Cost $ 30 excluding the power supply.
• Operational voltage 3.3, 5 and 12 volts.
• Laser intensity upto 10 W.

There might be many ways to make a mechanical shutter; I used eclipsing technique in which a shutter moves over and across an aperture through which the beam passes. To move the shutter I used an electric motor and a gear box. This method is relatively tuff because of the motor timing. While working on this I got couple of ideas of achieving the same goal: A 6 inches audio speaker with/without a micro controller can be converted in to a shutter (I will use this method if I plan to make a shutter for He-Ne) OR simply an electromagnet with a cantilever can be used as a shutter. The advantages of such a systems are, easy to make and similar in speed to commercially available systems.

Design

There are three major parts of the system.

• Shutter.
• Control box.
• Power supply.

The components used:

Shutter

• Glade automatic air spray: Air spray uses a motor and gearbox to mechanically operate the spray bottle.
• Thorlab Cage System Removable Filter Holders CFH1: To make shutter holder.
• Two 3 inches cage assembly rods: To install the shutter holder on the skin of air spray.
• Black aluminum foil: To make the shutter.

Control Box

• 2 3-pole on/off switch
• 1 Push on/off button
• 2 CD4013 4013 IC CMOS DUAL D FLIP FLOP IC
• 1 Resistor 100K Ohm
• 2 Resistor 10K Ohm
• 1 Resistor 100 Ohm trimmer (pot)
• 1 Resistor 1.5k Ohm
• 3 Resistor 240 Ohm
• 1 1N4148 diode
• 1 0.1uF 50V Ceramic Capacitor
• 1 222uF Radial Electrolytic Capacitor
• 1 npn KD-7B C1815 Y transistor
• 2 14 pin DIP IC Socket Adaptor Solder Type
• 2 RED LED 3mm
• 1 Yellow LED 3mm
• 1 A-5032 Prototyping Board 300x400 mm
• 1 12V relay
• 1.5m red, black, green and yellow wires
• 1 6X8 cm aluminum box.

Power Supply

I used 300W desktop computer power supply which i salvaged from an old computer.