Sunlight-powered (or at least sunlight-amplified) lasers

[tevarin]

I gotta find the original paper on this :)

http://www.engadget.com/2007/09/04/japanese-scientists-make-breakthrough-in-space-based-laser-power/

Comments

[anonymous]

Meh. Natural stellar lasers have been discovered. Surely it would be better to just reengineer the sun so that it would lase on command. ;)

--josh

[tevarin]

It worked in Ringworld :)

Natural stellar lasers are too big to be portable, though. I want one I can power from a backyard parabolic dish mirror.

[anonymous]

It worked in Ringworld :)

Yeah, you're an ME, dammit -- make me some scrith.

Natural stellar lasers are too big to be portable, though.

If you can build one, it's probably conveniently portable for you without having to be any smaller.

Anyway, I'm not really clear as to what they've got there. If it's merely collecting solar energy, converting it to electricity, and then powering a laser, then it's not very interesting. Strides could be made in efficiency, but really they'll just have a good solar power system and a good laser and neither necessarily has to be connected to the other.

OTOH, if they've figured out a way to take regular light and collimate it through some sort of magic lens or something, then that would be a breakthrough. Also, we could start having fun converting flashlights and such into laser guns.

--josh

[tevarin]

I found an abstract, at least:

Title: High-efficiency and economical solar-energy-pumped laser with Fresnel lens and chromium codoped laser medium
Author(s): Yabe T (Yabe, T.), Ohkubo T (Ohkubo, T.), Uchida S (Uchida, S.), et al.

Source: APPLIED PHYSICS LETTERS 90 (26): Art. No. 261120 JUN 25 2007

Language: English

Abstract: The authors achieved 11%-14% slope efficiency of solar-pumped laser by Cr-codoped Nd:yttrium aluminum garnet ceramic and Fresnel lens focusing from natural sunlight. The laser output of 24.4 W was achieved with 1.3 m(2) Fresnel lens. The maximum output for unit area of sunlight was 18.7 W/m(2), which is 2.8 times larger than previous results with mirror collector. The utilization of Cr3+ ion enabled efficient absorption and energy transfer to Nd3+ ion of solar spectrum. The fluorescence yield at 1064 nm for various pumping wavelengths was measured both for Crcodoped and nondoped laser media, and 1.8 times enhancement of laser output from sunlight is predicted. (c) 2007 American Institute of Physics.