PLEASE DON'T CROSS POST!

It all depends on your idea of cheap, of course. Are you seeing prices 2 times too high? 10 times? 100 times?

Why is efficiency a primary concern? One Watt is One Watt, irrelevant of efficiency.

CV

On the UV end, that is primarily Excimer land, which are quite inefficent. The 308nm XE-Cl's I am familiar with consume ~2KW AC to put out 30W average power. Other option there could be doubled or tripled diode pumped solid state (DPSS). Neither are cheap.

In the green visible, have you checked out diode lasers, guessing they are probably the most efficient.

Wheels within wheels / In a spiral array
A pattern so grand / And complex
Time after time / We lose sight of the way
Our causes can't see / Their effects.

sorry for cross posting, didn't know, won't happen again... efficiency is a primary concern, since 600w input to gain a milliwatt out is not my idea of energy efficiency, I'd prefer a more even balance.

for cost, I'm looking in the order of hundreds of pounds/dollars, rather than around the 20000 mark...

Well, you can rule out lasers altogether. Your only hope is to use filtered incoherent light, as you would obtain from an arc lamp or tungsten halogen lamp. You will only get Watts if you add up over a large spot (as compared to a laser).

Will your application support that? If you give your required spot size and irradiance (W/cm^2), I can be much more specific.

CV

thanks for the help... I'm after a cold light source, hence my point about efficiency, since, for example, 75 watts input with 1 watt output means I'm losing a lot of power as heat... so far as spot size goes, I want something that I can vary with fisheye lenses, which is why i wanted a laser which I could alter with lenses and mirrors....obviously I am yet to decide on that... I just wanted to know what was available so I could plan my reactor around it.... mercury lamps just aren't that efficient due to heat loss.....