Results 1 to 6 of 6

Thread: Diode temperature

  1. #1
    Join Date
    May 2008
    Location
    Sherbrooke, QC
    Posts
    17

    Default Diode temperature

    Hi everyone,

    I bought a cheap red laser diode (emission at 200mW but dropping to 150mW as it heats up) as well as a peltier junction. I want to experiment with TEC cooling.

    But I was wondering: I know lasers have warm-up times, so the crystals have to be at a certain temperature to efficiently lase. What is that temperature? 25C? 50C?

    Thanks

    Simon

  2. #2
    Join Date
    Jan 2006
    Location
    Charleston, SC
    Posts
    2,147,489,116

    Cool

    You're confusing DPSS laser operation with that of a direct injection diode. Your red is a direct injection diode - it doesn't have any crystals. You simply want to keep it cool.

    DPSS designs, on the other hand, often have a pair of peltier coolers. One is used to cool the diode, while the other is used to warm the frequency-doubling crystal. And yes, in this case the temperature control of the crystal (KTP, LBO, KNB03, or BiBO) is crucial. (The temperature of the lasing crystal, either YAG or Vanadate, is not nearly as important.)

    Bottom line, hook up your TEC and cool the didode as much as you can. Don't get too crazy though - you don't want to have to deal with condensation issues! But the colder the better in your case.

    Adam

  3. #3
    mixedgas's Avatar
    mixedgas is online now Creaky Old Award Winning Bastard Technologist
    Infinitus Excellentia Ion Laser Dominatus
    Join Date
    May 2007
    Location
    A lab with some dripping water on the floor.
    Posts
    9,468

    Default

    Quote Originally Posted by buffo View Post
    You're confusing DPSS laser operation with that of a direct injection diode. Your red is a direct injection diode - it doesn't have any crystals. You simply want to keep it cool.

    DPSS designs, on the other hand, often have a pair of peltier coolers. One is used to cool the diode, while the other is used to warm the frequency-doubling crystal. And yes, in this case the temperature control of the crystal (KTP, LBO, KNB03, or BiBO) is crucial. (The temperature of the lasing crystal, either YAG or Vanadate, is not nearly as important.)

    Bottom line, hook up your TEC and cool the didode as much as you can. Don't get too crazy though - you don't want to have to deal with condensation issues! But the colder the better in your case.

    Adam
    Dont fully drive the peltier on, use it a bit below its rated voltage and current, or it becomes a bit of a heat source on you. There is a curve to its response. pelteir cooler controllers are cheap.

    Steve

  4. #4
    Join Date
    May 2008
    Location
    Sherbrooke, QC
    Posts
    17

    Default

    Thanks for the info guys. The more you know

    Steve, I did a quick google search for peltier controllers and came up empty-handed. Could you recommend a particular company/supplier?

    I found a circuit diagram, so I could build one myself. It usually ends up being more expensive than just buying it, though.

  5. #5
    Join Date
    Oct 2006
    Location
    Central Florida
    Posts
    7,067

    Lightbulb

    Here is a lot of 10 that has already been sold...

    http://cgi.ebay.com/ws/eBayISAPI.dll...MEWA:IT&ih=011

    I think the guy has more.
    Love, peace, and grease,

    allthat... aka: aaron@pangolin

  6. #6
    Join Date
    Nov 2005
    Location
    Melbourne, Australia
    Posts
    3,702

    Default

    Quote Originally Posted by bulldog_99_00 View Post
    Thanks for the info guys. The more you know

    Steve, I did a quick google search for peltier controllers and came up empty-handed. Could you recommend a particular company/supplier?

    I found a circuit diagram, so I could build one myself. It usually ends up being more expensive than just buying it, though.
    Speak to Robin - uk-laser around these parts
    KVANT Australian projector sales
    https://www.facebook.com/kvantaus/

    Lasershowparts- Laser Parts at great prices
    https://www.facebook.com/lasershowparts/

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •