wtm@neoucom.UUCP (Bill Mayhew) (12/28/89)
Toshiba has a number of nice visible red laser diodes. The devices are capable of continuous operation with outputs of about 1 to 3 mW. The driving voltage is only a couple of volts with currents in the low mA range. The diodes can be operated from sources such as 9-volt batteries without many external components. The Toshiba diodes are four terminal devices that have a monitor photodiode built in for regualting output level. An op-amp and a few resistors and a capacitor to achieve slow turn-on are all that are required. There are several different grades of laser diodes available in various spectral output widths and beam patterns. The beam is typically an elipse with about 2-3 degrees in one direction and 20-30 degress on the other axis. Of course, eye safety considerations must be followed. We're considering building some laser pointers for use in teaching labs, but are still looking into the safety issues. Call your local Toshiba distributor and ask for the visible laser diode spec sheet. The current crop of laser diodes is a far cry from the IR output monsters of a few years ago that could only operate in pulse mode and required 25 or more amps to lase. Bill