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From: siegman@sierra.Stanford.EDU (Anthony E. Siegman)
Newsgroups: sci.electronics
Subject: Re: Can lasers be deflected electroMAGNETically?
Message-ID: <442@sierra.stanford.edu>
Date: 7 Jan 90 08:36:19 GMT
References: <6220004@hpcupt1.HP.COM>
Sender: siegman@sierra.STANFORD.EDU (Anthony E. Siegman)
Reply-To: siegman@sierra.UUCP (Anthony E. Siegman)
Organization: Stanford University
Lines: 13

Take a typical low-cost He-Ne or semiconductor-diode laser -- average
power is a few milliwatts (and only red is conveniently available --
blue or green still hard to obtain).  Spread that average light power
out to fill a reasonable TV screen size.  It will be so faint as to be
invisible. To put enough light onto a screen to have a good viewable
picture requires on the order of _watts_ of each color (obviously the
total power needed goes up with screen size).  Present-day visible
lasers with average power outputs in the few watt range cost
kilo-dollars and require kilowatts of electrical power input (not to
mention cooling water, short lifetime, etc.)

Laser projection TV may come, but not for a few years, until major
improvements in visible lasers have occurred.