Laser Diodes
Laser diodes such as these are all fabricated using semiconductor processes just like CPU and memory chips. Note that the VCSELs (vixels) produce a circular beam that couples well with a fiber.
A Tunable Laser Diode
Laser diodes also make great sensors. This laser diode from Jet Propulsion Labs is tunable to different frequencies in order to detect various gases both on this and other planets. (Image courtesy of JPL's Microdevices Laboratory; Robert M. Brown, photographer)
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