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I do apologize in advance as my computer is currently down due to hard drive failure at the time of this writing, so only text is available. As soon as I get it back up and going I'll post pictures. That being said...
A while back I got and rebuilt a 671nm laser, and loved the color of the 'true red' so I progressed onward and made a 680nm build, having wanted to explore the deeper end of the red spectrum-which seems to be ignored here a fair bit in favor of high power blues and such...red seems to have been lost to the wind over time.
I have always been a fan of Ruby lasers, which are the first laser systems to be created, but they are very high power, and very expensive...so you can't really run and appreciate the 'absolute red' color that the output. So I hunted around and decided to progress further down past the 680nm and 685nm diodes to find a similar power 690nm diode. Ruby lases at 694nm, so this is intended to be its direct replacement.
The diode in question is the HL6738MG made by Hitachi as part of the Opnext line. It is a 5.6mm, case negative diode and runs on about the same power as the 30mW 9mm 680nm circulaser diode I used before, sitting at a typical 2.5V @ around 90-100mA or so. I happened to have another LM1117 driver left at 109mA, so I thought I'd give it a go and take the plunge.
After some work tonight I built it into a 501B host, and turned it on and was rather floored by how 'red' it was. Truly beautiful deep red, a bit deeper than the 680nm greeted me. it is definitely fairly dim to the eye, so I was surprised by how bright it showed up after focusing. LPM shows its output at 40mW which is slightly more than its circulaser brother which is doing 22mW as I am not quite running it at full current. the beam profile is a nice ellipse like most reds, though this one isn't flat on the ends, nor does it have the 'wings' that most other reds have. Just a smooth clean oval shape.
On the wall its hard to destinguish from the other deep reds, but it is slightly 'redder' however, dispersing it in crystals or frosted glass etc yields a very dark red color. The beam is hard to see, but definiely barely visible in a dark room if your looking along the laser axis (facing toward/into the laser)
Overall, I'm very happy with this laser. its definitely beautiful to see despite the fairly high price. (not quite $60 IIRC) especially in the dark next to other reds, when your eye has no queues to use, its a brilliant ruby red, and I think I'll have a place in my collection for a long time to come :tinfoil:
Like the 680nm, the 690nm bleaches in photos, so don't expect too accurate of a color from this. But side by side with a HeNe makes the HeNe dot look virtually completely orange!
Pics!
The Diode! (5.6mm TO-CAN style)
Relatively unfocused:
more focused....
There!
Some stainless steel reflections from a sliding pan:
With 532nm 4-5mW in a blue bucket of industrial auto glass wash:
This isn't a bad rendition of the color, but its still a bit more red than this. Shining it into the red drink seems to have helped.
So then how does it compare to in a Bottle of water?
A while back I got and rebuilt a 671nm laser, and loved the color of the 'true red' so I progressed onward and made a 680nm build, having wanted to explore the deeper end of the red spectrum-which seems to be ignored here a fair bit in favor of high power blues and such...red seems to have been lost to the wind over time.
I have always been a fan of Ruby lasers, which are the first laser systems to be created, but they are very high power, and very expensive...so you can't really run and appreciate the 'absolute red' color that the output. So I hunted around and decided to progress further down past the 680nm and 685nm diodes to find a similar power 690nm diode. Ruby lases at 694nm, so this is intended to be its direct replacement.
The diode in question is the HL6738MG made by Hitachi as part of the Opnext line. It is a 5.6mm, case negative diode and runs on about the same power as the 30mW 9mm 680nm circulaser diode I used before, sitting at a typical 2.5V @ around 90-100mA or so. I happened to have another LM1117 driver left at 109mA, so I thought I'd give it a go and take the plunge.
After some work tonight I built it into a 501B host, and turned it on and was rather floored by how 'red' it was. Truly beautiful deep red, a bit deeper than the 680nm greeted me. it is definitely fairly dim to the eye, so I was surprised by how bright it showed up after focusing. LPM shows its output at 40mW which is slightly more than its circulaser brother which is doing 22mW as I am not quite running it at full current. the beam profile is a nice ellipse like most reds, though this one isn't flat on the ends, nor does it have the 'wings' that most other reds have. Just a smooth clean oval shape.
On the wall its hard to destinguish from the other deep reds, but it is slightly 'redder' however, dispersing it in crystals or frosted glass etc yields a very dark red color. The beam is hard to see, but definiely barely visible in a dark room if your looking along the laser axis (facing toward/into the laser)
Overall, I'm very happy with this laser. its definitely beautiful to see despite the fairly high price. (not quite $60 IIRC) especially in the dark next to other reds, when your eye has no queues to use, its a brilliant ruby red, and I think I'll have a place in my collection for a long time to come :tinfoil:
Like the 680nm, the 690nm bleaches in photos, so don't expect too accurate of a color from this. But side by side with a HeNe makes the HeNe dot look virtually completely orange!
Pics!
The Diode! (5.6mm TO-CAN style)
Relatively unfocused:
more focused....
There!
Some stainless steel reflections from a sliding pan:
With 532nm 4-5mW in a blue bucket of industrial auto glass wash:
This isn't a bad rendition of the color, but its still a bit more red than this. Shining it into the red drink seems to have helped.
So then how does it compare to in a Bottle of water?
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