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M140 Diode

CurtisOliver

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I have three questions to ask please.
1.Is the new 470nm blue, better looking than the 445nm one?
2. Is the 470nm 's diode more robust than the 445's?
3. There is a possibility to choose between one 7W 445nm and one 5W 470nm.Which you think is more sensible purchase?
1) Well that's up to personal preference. 445: |||||||||||| 470: ||||||||||||
445nm is deep blue/indigo while 470nm is blue/light blue.

2) This is highly dependent on the diode so can't say unless comparing two specific diodes. But it should be noted that NUBM07's need to driven at high current to meet and exceed 470nm as they are typically 465nm. Current and temperature can shift a diodes central wavelength but this involves pushing them hard. NUBM07's have a wavelength range of 462-473nm. Also NDB7675's have been known to hit as high as 476nm but it is not recommended to push them that far. Their normal range is 456-469nm with most at 462nm.

3) Again this is your personal preference. The 450nm NUBM44 is a scary laser to own, and the NUBM07 is a beautiful and high power also. Are you after a power burner or a strong blue beam?
 

CurtisOliver

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Thanks Peter. :) At 5W, 470nm is definitely doable and within a sensible range. I really should compare my NUBM07 one day to my 473nm DPSS and see how far off it is.
 

GSS

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It's funny you put some great info in your signature there;s no more room for your laser's signature of yours:giggle:
473nm to 476nm just seems the prettiest beam color to me by far.
 

CurtisOliver

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That graph is nearly my entire laser collection. Every dot is one laser. But if you have more than one of the same wavelength and power then it shows up as one. This mainly applies to the multiple red keychain type lasers I have. :p That spectrum is the easiest way of seeing what I have.

That part (473-476nm) of the spectrum is very nice. To be honest any wavelength beyond 460nm is really nice to look at in its own right. You start to lose that violet tinge and then the spectrum accelerates towards cyan.
 
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paul1598419

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It should also be noted that 465nm is more visible mW for mW than 445nm. But, a decanned 445nm laser diode has been shown to have a short lifespan when compared to an intact diode.
 

CurtisOliver

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Yes indeed 465nm is brighter, both in daylight and in nighttime conditions.
 

Theodore41

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1) Well that's up to personal preference. 445: |||||||||||| 470: ||||||||||||
445nm is deep blue/indigo while 470nm is blue/light blue.

2) This is highly dependent on the diode so can't say unless comparing two specific diodes. But it should be noted that NUBM07's need to driven at high current to meet and exceed 470nm as they are typically 465nm. Current and temperature can shift a diodes central wavelength but this involves pushing them hard. NUBM07's have a wavelength range of 462-473nm. Also NDB7675's have been known to hit as high as 476nm but it is not recommended to push them that far. Their normal range is 456-469nm with most at 462nm.

3) Again this is your personal preference. The 450nm NUBM44 is a scary laser to own, and the NUBM07 is a beautiful and high power also. Are you after a power burner or a strong blue beam?
Thank you very much for your response.
As for the divergence which is bigger?I have already a 3X BE to use with the laser which I decide to buy,ie either the 445 or the 470nm.(I think that I will go for the 470nm).
 

CurtisOliver

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You're welcome. The NUBM07 has better divergence than the NUBM44. Can't remember the exact specs but the the 450nm M44 has a large divergence. This also depends on what lens you use.
 

hakzaw1

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when asked where to find/learn --99% of the time we say..make our search function your new best friend..
'Search' does not mind answering a question that has been asked MANY times.
btw your new diode may have already gotten damaged when you handled it..search 'ESD precautions'
AND if you think 5.6 (which is the mm) is small look at the 3.8mm!!
 

paul1598419

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I never think of the TO-18 case diodes as being small. The first time I saw a TO-38, I thought it was a bit small, but that means your module will be able to handle the waste heat from the diode better.
 

Benm

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There is a fair point in smaller laser packages becoming problematic for cooling though, especially with high power diodes.

The surface area of a diode package is proportional to it's radius multiplied by it's height. This is usually a fairly small area, and you need to overcome thermal resistance here regardless of what you do after it (module to air, bolted to heatsink, TEC, water cooling or whatever you want).

The 5.6 mm form factor was pretty convenient for this, having enough surface area to make the thermal resistance between diode housing and next stage of heatsinking not that significant, especially when using a small amount of thermally conductive paste to bridge any gaps.

Be careful with the names of electronic parts though: TO18 does not means something like 1.8mm diameter, it's in fact about 5.6mm wide diameter. These are just designations. The standard package for a through hole mounted transistor is TO-92, which is not even round, and larger than most laser resistors. TO-3 is a huge form factor for power transistors.

The lack of a consistent system can be very confusing, so triple check the sizes before buying any combination of laser and module/heatsink!
 

paul1598419

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You have to be kidding, right? Of course I know what the case number designations for laser diode and transistors stand for. I've been dealing with these designations all my life. Yes, the TO-38 has a smaller surface area, but the surface area for all diodes is the disk they are mounted on that is in contact with any kind of heat sink. You can't go by the entire area of a laser diode as most of that is never in contact with a module or a sink. There are also TO-3 packages for laser diodes too, but the only part that contacts the sink is the under surface area.
 

chloderic

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You have to be kidding, right? Of course I know what the case number designations for laser diode and transistors stand for. I've been dealing with these designations all my life. Yes, the TO-38 has a smaller surface area, but the surface area for all diodes is the disk they are mounted on that is in contact with any kind of heat sink. You can't go by the entire area of a laser diode as most of that is never in contact with a module or a sink. There are also TO-3 packages for laser diodes too, but the only part that contacts the sink is the under surface area.
so it is .....
 

Benm

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Well yeah, if you've been working with electronics a lot you know that the TO designation number does not reflect the diameter in mm or something like that... but to someone new to the hobby they might very well think so, especially since TO-56 is 5.6 mm diameter and very common for laser diodes.

And that's just the external form factor... The TO-3 format is an excellent example of how confusing this can get. Normally you get a TO-3 transistor with the housing being the collector and 2 pins for emitter and base. But they also make things in the same form factor with more than 2 pins, even laser technology where you have, for example, both a TEC and a laser diode in in single package but with more than 2 pins.

You also have TO-3 sized devices with many more pins, like integrated audio amplifiers and such, making the whole numbering scheme extremely confusing - at least compared to that for say lithium cells where you can tell the dimensions right off the format number.
 
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