505nm and 480nm diode RESULTS

That Sucks. Hopefully it gets sorted out quickly so we can all see the results of your testing.

Well, I've given up for the weekend. It shows it as delivered, but it wasn't delivered to me. I spent hours on the phone trying to talk to the post office with no success. I tried to phone and email the main office for the USPS with no luck, what so ever. I will have to pick it up again on Monday to try to find out where my package was delivered.

Oh my that is terrible, of all the packages in the world being posted it had to be this one that is walkabouts, Dam!

Ooooch, sorry to hear that Paul. That's got to be an exercise in patience. Makes for a long weekend. Hopefully it will get worked out before than. Hoping the best.

Ever screw up and wonder how many people you pissed off due to that error....? Just imagine. A mailman delivers a package to the wrong address in Washington state and people around the world feel the pain. Talk about your ears burning haha.

No one is more pissed off than I am. I spent hours on the phone trying to get it resolved today before all the post offices closed for the weekend. I had plans of spending a large chuck of time analyzing this diode only to have to wait for Monday morning to try again. I have doctor's appointments next week and they aren't close by or will be over quickly. This is going to screw up my whole day Monday too.

paul1598419 said:

No one is more pissed off than I am. I spent hours on the phone trying to get it resolved today before all the post offices closed for the weekend. I had plans of spending a large chuck of time analyzing this diode only to have to wait for Monday morning to try again. I have doctor's appointments next week and they aren't close by or will be over quickly. This is going to screw up my whole day Monday too.

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Damn post offices. Don't think I've ever had a pleasant experience with one. Hopefully it turns up and you get it all figured out.

Hope everything is OK at the docs too! :beer:

Hi guys,

it is my first post but I have been around for some months here. I am a researcher and need single mode and single frequency (I will build them into an ECDL to narrow them down) diodes at 461nm, 497nm and 481nm for my new experiment. The last two wavelengths are only accessible trough frequency doubling, what is complex and expensive. And now you guys came up with these greta diodes that could be in the range I need.

I will by 5-10 of the 505nm and charakterize them. I have all the equipment you need for a full spec sheet like you get from the supplier. In Addition I also tune through temperature (1nm per 100mA). Hope to share the data with you when I have them

@ lazerman121 and paul1598419: Could you give me the contact to the supplier of the 480nm diodes so I can run also the characterization on them and share it here?

Best regards

Welcome to the forum Singlemode Laser.
May I ask why those very specific wavelengths? Sounds interesting.
Just so you know, these 480's seem to be falling short, but with temperature tuning you may get to 481nm still. But these haven't been tested yet, with that much overcurrent.
Anyway, feel free to introduce yourself in the welcome section. :beer:

462nm is very close to your 461nm goal. The 505's may be able to be cooled to 497nm. And these supposed 480's may be able to produce the 481nm.

Singlemode Laser said:

@ lazerman121 and paul1598419: Could you give me the contact to the supplier of the 480nm diodes so I can run also the characterization on them and share it here?

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Actually, I don't think Paul has any contact with them, however I do. My source has requested I don't put their name out there for everyone to see and bombard them with emails, however it seems like you do have a legitimate need to be in contact with them. PM coming.

To add to curtisoliver's post:

461nm is easily attainable in multimode diodes. Single mode may be a little challenging to find...

481nm may be able to be overdriven to reach these. So far, the highest wavelength diode the supplier was aware of is 478nm. Heat and more current should be able to bump it 3nm... however, overdriving will reduce lifespan when pushed hard.

497nm... that one is the tough one. Their 505nm diodes are in the range as advertised by the looks of it, which means cooling is the only option. And a lot of it. You'll need to build some enclosure that will basically turn it into a block of ice. Or dry ice. You'll need to consider moisture with the design on that.

ZRaffleticket said:

Actually, I don't think Paul has any contact with them, however I do. My source has requested I don't put their name out there for everyone to see and bombard them with emails, however it seems like you do have a legitimate need to be in contact with them. PM coming.

To add to curtisoliver's post:

461nm is easily attainable in multimode diodes. Single mode may be a little challenging to find...

481nm may be able to be overdriven to reach these. So far, the highest wavelength diode the supplier was aware of is 478nm. Heat and more current should be able to bump it 3nm... however, overdriving will reduce lifespan when pushed hard.

497nm... that one is the tough one. Their 505nm diodes are in the range as advertised by the looks of it, which means cooling is the only option. And a lot of it. You'll need to build some enclosure that will basically turn it into a block of ice. Or dry ice. You'll need to consider moisture with the design on that.

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Yep, totally forgot about the multi-mode aspect. Thank you. And yes, 497nm would be tough. There are 498's out there but they are very hard to get hold of and cost an arm and a leg.

Hi,

the experiment will be the an optical clock based on laser cooled Strontium atoms. These clocks are the most precise clocks in the world and are already x1000 better than the cesium fountains with a lot of room for further improvement (I wont beat this performance in the next years of coarse) This experiments goal is to lean as much as you can about the system and try out new things and schemes, to gain the knoledge for a 2nd gen. experiment with much better performance.

497nm or 481nm can be used as a very efficient way to increase the atom number and do other fancy things. A direct diode source is much simpler than a frequency doubling source that needs a diode laser at twice the wavelength, an diode amplifier and a resonant cavity + a lot of electronics and is bulky and not very flexible. These diodes have a great beam profile and with cylindrical lenses I can easily get >60% of the light into a single mode fiber (this is necessary to decouple the chamber from the electronics.

I don't need the exact wavelength, since I will integrate the diodes in an ECDL (wavelength selective feedback from a tunable grating) anyway to reduce the line width to < 1MHz. With this I am able to reach operation +/- 3 to 5 nm fro m the free running wave length (the output power is educed though) . Actually, based on this forum I found the PLT5 450B and figured out that you can operate these diode at at least twice the spected current and the PI slope is still linear. So I bought 3 from DTRs shop, check the wavelength, took the one with the highest WL (458.2nm) and its operating now at 461nm nicely. I know I got very lucky to get one of three and I need some more for the future. In the worst case I buy a pack with 200 of them and let them characterized. Still much more cheaper than the selected ones from Nichia.

Temperature tuning is also possible but this will bring me maximum +2 nm (if I tune from 20°C to 60°C) but this will reduce the lifetime of the diode and they have to operate at least a year (always on), so we don't spent half of our time with replacement.

Sorry for the long answer. Feel free to ask me if you need more details.

Now that moisture-proof design has been done by a member here before to cool a red-orange diode into the orange range, in a controlled environment. Can't say by who. It isn't impossible.... but it's no easy task. It sounds like singlemode laser knows his stuff, so I just wanted to cover a little that could potentially be overlooked

But yeah, buying a native 495nm-ish diode isn't within reason at present.




Edit: new post above:

You did get lucky with the 461nm. It sucks that buying 200 of them at a time is cheaper right now. Just the name of the game. A few years ago people would call you nuts for expecting diodes like these... maybe in 5 more years you'll find steady sources for these more exotic wavelengths. After being around for 7 years on here, I'm still calling myself nuts.

Seems you have this all down pat then. So this is more production questions than proof-of-concept. Then yeah. You might want to see if any suppliers for the 505nm diodes will bin low-wavelength ones for you pre-purchase. Though I wouldn't expect anything lower than 501nm on the 505's. Many places won't bin either, but some will if you're on good terms with them and if they're bored. Sadly, temperature tuning is the only real way to tune a wavelength down on diodes, apart from underdriving them (which doesn't do as much as it is within expected operating conditions for the diodes)

Styropyro most likely who you going on about Zraffleticket.


Very nice Singlemode Laser. Thanks for posting. +rep to you when I can. Now I understand the need for specific wavelengths.
I like the laser cooling of sodium by using 589nm. Please feel free to share this project on here.

CurtisOliver said:

Styropyro most likely who you going on about Zraffleticket.

Very nice Singlemode Laser. Thanks for posting. +rep to you when I can. Now I understand the need for specific wavelengths.
I like the laser cooling of sodium by using 589nm.

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Nope Controlled is the key word for that. It was a full enclosure using a lot of TEC options. It was most certainly not posted anywhere

ZRaffleticket said:

Actually, I don't think Paul has any contact with them, however I do. My source has requested I don't put their name out there for everyone to see and bombard them with emails, however it seems like you do have a legitimate need to be in contact with them. PM coming.

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Thanks a lot for this. I wont share this information with others.

ZRaffleticket said:

To add to curtisoliver's post:

461nm is easily attainable in multimode diodes. Single mode may be a little challenging to find...

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Yes I kno, but I need single mode diodes for efficient coupling of the light into a sm fiber. The beam profile form the 1.6W Osram 450nm diode seems nice and plan to buy one and measure the portion of the TM00 mode with a beam profiler

ZRaffleticket said:

481nm may be able to be overdriven to reach these. So far, the highest wavelength diode the supplier was aware of is 478nm. Heat and more current should be able to bump it 3nm... however, overdriving will reduce lifespan when pushed hard.

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I allready wrote answer about this to CurtisOliver. I will put them in a ECDl setup, so I can pull the wavelength up to 5nm

ZRaffleticket said:

497nm... that one is the tough one. Their 505nm diodes are in the range as advertised by the looks of it, which means cooling is the only option. And a lot of it. You'll need to build some enclosure that will basically turn it into a block of ice. Or dry ice. You'll need to consider moisture with the design on that.

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You are right if it would be just the diode without feedback. So If can can get one that runs at 502-503 I don't need temperature tuning at all. There some paper out there with ECDLs tunable by 40nm by cooling them to -80°C in a vacuum enclosure

Thanks again and feel free to ask