Optical Communication in Free Space

Overview

Forum Link http://www.knoxvillehackerspace.com/phpbb/viewtopic.php?f=6&t=13

Milestones

Range

• Demonstrate point to point communications across a room with Class IIIa lasers and no optics
• Demonstrate point to point communications across a field with Class IIIa lasers and optics present
• Determine distance limitations of point to point communications using Class IIIa lasers
• Procure Class IIIb lasers and necessary protective gear and attempt longer range communications

Data Transfer Rate

Half Duplex

• Go/No Go with simple breadboard circuit
• Simple voice communication with modulator and amplifier circuits
• High speed network communications

Full Duplex

• Go/No Go with simple breadboard circuit
• Simple voice communication with modulator and amplifier circuits
• High speed network communications

Optics

Transmitter

Lasers

A 5 mW green laser pointer is available from http://www.optotronics.com/green-laser-pointers.php with very good beam properties Beam divergence: <1.2 mrad Beam diameter: <1.5 mm

• Add equations for divergence and maybe wolfram alpha application for calculations

External Links

Ronja Project http://ronja.twibright.com/

http://members.misty.com/don/laserfaq.htm

http://www.repairfaq.org/sam/laserdps.htm

http://captain.haddock.8m.com/laser/laser1.html