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FrozenGate by Avery

Mitsubishi 638nm 300mW CW

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I searched and didn't find this mentioned here on lpf yet, it's not exactly new (Sample Shipments began shipping June 1st, 2009) but it's still interesting. Designed for small laser projectors, it's the industrys' strongest diode at 300mW CW with a case temperature of 45*C. It appears to be a multi-mode diode though, based on this line near the bottom: "Laser specifications: Lateral multimode". At only ¥30,000 per, before taxes ($324.57usd) they aren't cheap, but they'd sure be interesting to test with, see what might be achieved with pushing them to their limits.

Optical Devices | Product Information | MITSUBISHI ELECTRIC SEMICONDUCTORS

Edit: Seems just the price is the problem then :whistle:
 
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Lateral multimode isn't the same as transverse multimode though.

Most laser diodes (like the ones from dvd drives) mode-hop laterally all the time. With temperature changes the wavelength also varies, so a different number of waves fit between the mirror facets.

These diodes sound very nice, hope the prices come down a bit though ;)
 
Actually the price sounds pretty good to me when you consider its 638nm rated for 300mW CW. But then again, i won't be buying one :p
 
is multi modal so no good to use.

they do a 130mw cw single mode version which is £105
 
The lateral multimode meaning means it is fine for display, but will not work for holography. Transverse multimode is the hard one, you get a fat beam, and need a cylin der lens to fix it too. I found that most diodes, especially ones over 100mw are not very coherent sue to oscillations in the electric flow through the die. It means the wavelength shifts slightly over time, and in part of the beam giving it a poor coherence length.

Bottom line, good for laser pointers, displays, and projectors- the stuff 99% of us would use it for; Lousy for holography, metrology, and spectroscopy.
 
disagree, why would you want a big fat beam for a projector?

most of the beam gets lost off the galvo mirrors and it not great for mixing with other colours / smaller beams
 
He's saying there are two types of "multimode": multi-transverse and multi-lateral. Multi-transverse gives the fat beam.. multi-lateral gives a nice beam, but crappy coherence length. Every commonly available "singlemode" diode is single-transverse mode and multi-lateral (aka multi-longitudinal) mode. These are no different in terms of mode than any dvd diode and they will give a good beam.
 
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Indeed... for pointers and projectors, the transverse mode is important. Diodes that are multimode transversely give the big beams, often square or rectangular in shape, as opposed to the near gaussian output pattern of single transverse mode diodes.
 
funny, almost no response.. this seems to be the brightest red (singlemode) diode available! I bet the people on photonlexikon are all over it already! :-)

manuel
 
They have a press release on their new 500mW CW.

are these 300mW ones available in any drives, or only in projectors?
 
I wonder if they would lower the price for a GB. I really want to build a red that is twice as bright as my 230mW LOC. The price might actually be worth it though since it would be hard to find a host for a 9mm ot c-mount 635nm.
 
I suppose $300 is still pretty steep for a red diode, even one with these specs.

I'm sure there will be much more interest when prices come down, like we've seen with the 445 nm casio diodes. For me they are to expensive to just start mucking with, since i've known myself to blow up a LD once in a while due to user error mostly ;p
 
You will need 4 X 230mw to get an effective, and perceivable brightness that was two times the amount of one LOC.

Yes, 1W of 660nm light will be TWICE as bright as 250mws. You may be better off going with 636nm, or 642nm.

I believe 640nm is available in DPSS.
 
Meatball said:
You will need 4 X 230mw to get an effective, and perceivable brightness that was two times the amount of one LOC.

Yes, 1W of 660nm light will be TWICE as bright as 250mws. You may be better off going with 636nm, or 642nm.

I believe 640nm is available in DPSS.
Click to expand...

The diodes mentioned in the OP are 638nm.
 
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