Laser pointer discussion. Read/write reviews of laser pointers and laser pointer companies. Learn about all types of laser pointers and lasers





Welcome to Laser Pointer Forums! If you are looking for a laser pointer or want to compare different laser pointer companies, you may want to check out the LPF Laser Pointer Company Database. The link will open in a new window for your convenience.








Green Laser Pointers by Category Blue Laser Pointers by Category Red Laser Pointers by Category
Yellow Laser Pointers by Category Violet Laser Pointers by Category Orange Laser Pointers by Category
Top Laser Pointers by Power - 1 Watt+ Top Laser Pointers by Power - 500mW+ Top Laser Pointers by Power - 250mW+
Laser Pointer Database High Power Laser Pointers Laser Pointer Diodes
Laser Technology Laser Pointer Parts Lasers by Wavelength
Top 10 Laser Pointer Companies Laser Pointer Company Database Visible Beam Laser Pointers


One laser store meets all your needs

























Go Back   Laser Pointer Forums - Discuss Laser Pointers > Lasers > General



LPF List of Laser Pointer Companies (link opens new window)



Reply
 
LinkBack Thread Tools Display Modes
Old 07-13-2016, 12:15 PM #1
Junior Member
 
Join Date: Jul 2016
Posts: 2
Rep Power: 0
Rocket is on a distinguished road
Rocket Rocket is offline
Junior Member
 
Join Date: Jul 2016
Posts: 2
Rep Power: 0
Rocket is on a distinguished road
Default [Newbie] >1W Blue/Green diode collimated for small spot size 50-100m away

Hi there. I'm toying with the idea of using a cheap blue/green diode to check my homemade submersible isn't heading towards anything that isn't water. Not a Lidar system, just measuring the reflected light. My back-of-envelope calculations suggest a 1-2W laser will give me a detectable photocurrent out to 50-100m BUT I have two problems....

1) what should i be looking for in an LD for getting a great collimation (445/450 or 532 - don't really mind - although I would get a stronger photocurrent from the green per watt of laser power) is there an obvious candidate?

2) the diode is going to be in a vacuum and I want to run it continuously. Can you do that with a copper host? I'd mount it on a TEC and get the heat elsewhere but are the hosts sufficiently efficient to keep lasing continuously (for an hour or more)?

Bit of a random first post but there seems to be a depth of wisdom on these forums that is worth tapping

Many thanks for any insights/tips you guys may have....


Rocket is offline   Reply With Quote







LPF List of Laser Pointer Companies (link opens new window)







Old 07-13-2016, 02:27 PM #2
diachi's Avatar
Class 4 Laser
 
Join Date: Feb 2008
Location: Yellowknife, NT, Canada
Posts: 7,930
Rep Power: 26790
diachi has a reputation beyond reputediachi has a reputation beyond reputediachi has a reputation beyond reputediachi has a reputation beyond reputediachi has a reputation beyond reputediachi has a reputation beyond reputediachi has a reputation beyond reputediachi has a reputation beyond reputediachi has a reputation beyond reputediachi has a reputation beyond reputediachi has a reputation beyond repute
Send a message via Skype™ to diachi
diachi diachi is online now
Class 4 Laser
diachi's Avatar
 
Join Date: Feb 2008
Location: Yellowknife, NT, Canada
Posts: 7,930
Rep Power: 26790
diachi has a reputation beyond reputediachi has a reputation beyond reputediachi has a reputation beyond reputediachi has a reputation beyond reputediachi has a reputation beyond reputediachi has a reputation beyond reputediachi has a reputation beyond reputediachi has a reputation beyond reputediachi has a reputation beyond reputediachi has a reputation beyond reputediachi has a reputation beyond repute
Send a message via Skype™ to diachi
Default Re: [Newbie] >1W Blue/Green diode collimated for small spot size 50-100m away

Is there a reason you can't go with some sort of sonar?
__________________


405nm | Banggood LT-850 | "5mW" | Review Unit | Review WIP
445nm | Sanwu Laser Pocket Series | 400mW Metered
445nm | NDB7242E Pen Build | 60mW Metered | >>Build Thread<<
450nm | LaserPointerStore - Thor H2 | 1W(?) | Review Unit | >>Review<<
488nm | Spectra Physics 163 Argon | ~30mW Metered
515nm | PL515 Pen Build | 50mW Metered | >>Build Thread<<
520nm | Laserlands 520 | 5mW | Review Unit | 3mW metered | >>Review<<
532nm | Gearbest 303 Pointer | 50mW Metered
532nm | Gearbest JD-850 Pointer | 30mW Metered (I think, need to re-test).
633nm | HeNe | 6mW
633nm | Spectra Physics 155 HeNe | <1mW >>Thread<<
650nm | Sanwu Laser Pocket Series | 200mW Metered
808nm | Melles Griot 532nm Lab Unit | No Crystals >10W | X2



Check out my Reddit Subreddit! >>/r/laserpointers<<

diachi is online now   Reply With Quote
Old 07-13-2016, 03:02 PM #3
Junior Member
 
Join Date: Jul 2016
Posts: 2
Rep Power: 0
Rocket is on a distinguished road
Rocket Rocket is offline
Junior Member
 
Join Date: Jul 2016
Posts: 2
Rep Power: 0
Rocket is on a distinguished road
Default Re: [Newbie] >1W Blue/Green diode collimated for small spot size 50-100m away

I've currently got everything in a single vacuum glass tube so a sonar unit would need to be attached to the front of the submersible and linked to the brain of the unit in the pressure housing. a sonar unit is also heavier, costs more and requires more signal processing than a relatively cheap LD+photodiode.

it just feels the right design choice if i can get it to work.

The operating depth is a few 1000m so having a single pressure vessel is heaven.
Rocket is offline   Reply With Quote
Old 07-13-2016, 03:44 PM #4
diachi's Avatar
Class 4 Laser
 
Join Date: Feb 2008
Location: Yellowknife, NT, Canada
Posts: 7,930
Rep Power: 26790
diachi has a reputation beyond reputediachi has a reputation beyond reputediachi has a reputation beyond reputediachi has a reputation beyond reputediachi has a reputation beyond reputediachi has a reputation beyond reputediachi has a reputation beyond reputediachi has a reputation beyond reputediachi has a reputation beyond reputediachi has a reputation beyond reputediachi has a reputation beyond repute
Send a message via Skype™ to diachi
diachi diachi is online now
Class 4 Laser
diachi's Avatar
 
Join Date: Feb 2008
Location: Yellowknife, NT, Canada
Posts: 7,930
Rep Power: 26790
diachi has a reputation beyond reputediachi has a reputation beyond reputediachi has a reputation beyond reputediachi has a reputation beyond reputediachi has a reputation beyond reputediachi has a reputation beyond reputediachi has a reputation beyond reputediachi has a reputation beyond reputediachi has a reputation beyond reputediachi has a reputation beyond reputediachi has a reputation beyond repute
Send a message via Skype™ to diachi
Default Re: [Newbie] >1W Blue/Green diode collimated for small spot size 50-100m away

Quote:
Originally Posted by Rocket View Post
I've currently got everything in a single vacuum glass tube so a sonar unit would need to be attached to the front of the submersible and linked to the brain of the unit in the pressure housing. a sonar unit is also heavier, costs more and requires more signal processing than a relatively cheap LD+photodiode.

it just feels the right design choice if i can get it to work.

The operating depth is a few 1000m so having a single pressure vessel is heaven.

My concern would be reflections/low transmittance in the water. If there's a lot of silt or other particles in the water your photodiode may detect reflections from those, and depending on on how 'murky' the water is, the beam may not even make it as far as you need - and back. The diffuse reflection has to make it all the way back to the source too and it's not going to be a nice tight beam. If you're using returned intensity to figure out the distance that's definitely not going to work as the intensity will vary depending on transmittance.

I've never used a laser under water like that so I'm really not entirely sure, maybe someone else here has - truth be told I don't much like the water!

For sonar - I'm not talking of some sonar imaging system, just a basic sonar rangefinder - that shouldn't require a ton of signal processing and should be a hell of a lot cheaper than a proper sonar imaging system. I imagine a cheap sonar transducer and something like an arduino might be able to take care of it. That'll certainly be lighter, less power hungry and cheaper than 1W of 520nm, a heatsink for the 520, driver for the 520, TEC, TEC driver and power source for the TEC + driver. One problem with that approach may be a lack of "directivity" - you may just know that something is within "X distance" - but not where it is.
__________________


405nm | Banggood LT-850 | "5mW" | Review Unit | Review WIP
445nm | Sanwu Laser Pocket Series | 400mW Metered
445nm | NDB7242E Pen Build | 60mW Metered | >>Build Thread<<
450nm | LaserPointerStore - Thor H2 | 1W(?) | Review Unit | >>Review<<
488nm | Spectra Physics 163 Argon | ~30mW Metered
515nm | PL515 Pen Build | 50mW Metered | >>Build Thread<<
520nm | Laserlands 520 | 5mW | Review Unit | 3mW metered | >>Review<<
532nm | Gearbest 303 Pointer | 50mW Metered
532nm | Gearbest JD-850 Pointer | 30mW Metered (I think, need to re-test).
633nm | HeNe | 6mW
633nm | Spectra Physics 155 HeNe | <1mW >>Thread<<
650nm | Sanwu Laser Pocket Series | 200mW Metered
808nm | Melles Griot 532nm Lab Unit | No Crystals >10W | X2



Check out my Reddit Subreddit! >>/r/laserpointers<<


Last edited by diachi; 07-13-2016 at 03:44 PM.
diachi is online now   Reply With Quote
Reply





Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On











Loading








Green Laser Pointers by Category Blue Laser Pointers by Category Red Laser Pointers by Category
Yellow Laser Pointers by Category Violet Laser Pointers by Category Orange Laser Pointers by Category
Top Laser Pointers by Power - 1 Watt+ Top Laser Pointers by Power - 500mW+ Top Laser Pointers by Power - 250mW+
Laser Pointer Database High Power Laser Pointers Laser Pointer Diodes






Privacy Policy | Advertising Disclaimer | Terms of Use


 


All times are GMT. The time now is 12:33 AM.


Powered by: vBulletin
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.
Search Engine Friendly URLs by vBSEO
Privacy Policy | Advertising Disclaimer | Terms of Use
Copyright (C) 2017 Laser Pointer Forums, LLC