"optical" - key terms from Wikipedia

asahi optical
high definition optical	disc
nintendo optical	disc
nonlinear optical
optical
optical	activity
optical	amplifier
optical	axis
optical	camouflage
optical	carrier
optical	cavity
optical	character recognition
optical	coherence tomography
optical	communication
optical	communications
optical	density
optical	disc
optical	drive
optical	drives
optical	effects
optical	fiber
optical	frequency
optical	heterodyne detection
optical	illusion
optical	illusions
optical	media
optical	mice
optical	microscope
optical	microscopy
optical	modules
optical	mouse
optical	network
optical	phase conjugation
optical	phenomena
optical	phenomenon
optical	power
optical	printer
optical	quality
optical	seti
optical	sight
optical	signal
optical	sound
optical	storage
optical	system
optical	systems
optical	telescopes
optical	tracker
optical	zoom
passive optical	network
synchronous optical	networking