808nm 200mw laser diode circuit help

[navedjh]

i need to design a medical device for dental treatment using laser diode , kindly help me in circuit designing

 

[Jirkas99]

Hi,
You could use LM317 to make simple current regulator (I had succes even with two transistors and resistors just search on google for constant current).. But I just have to ask. Why? If you are engineer then you wont ask here on LPF for such simple thing as constant current driver(even though I think they use pulsed lasers but I am not sure). And If you are dentist I am sure there are a lot of these devices on market already and that you don't want to burn hole through customers face.
J

 

[paul1598419]

i need to design a medical device for dental treatment using laser diode , kindly help me in circuit designing

Medical lasers need to pass stringent tests before they get approved. You should already know this if you are legit. Also, you have given far too little information for anyone to offer you any help. You haven't even said what you hope this laser will accomplish.

 

[navedjh]

Hi,
You could use LM317 to make simple current regulator (I had succes even with two transistors and resistors just search on google for constant current).. But I just have to ask. Why? If you are engineer then you wont ask here on LPF for such simple thing as constant current driver(even though I think they use pulsed lasers but I am not sure). And If you are dentist I am sure there are a lot of these devices on market already and that you don't want to burn hole through customers face.
J

yes there are so many circuits on google for constant current supply but i need suggestion which circuit can be best for laser dental healing process.. i am looking to design a device in which healing can be done gingival tissue while using 808nm laser diode. and i need to operate the device with any micro controller to control its pulse frequency and show the average output power and on timing of laser on any display

 

[navedjh]

Medical lasers need to pass stringent tests before they get approved. You should already know this if you are legit. Also, you have given far too little information for anyone to offer you any help. You haven't even said what you hope this laser will accomplish.

what they are ...could you breif me

 

[navedjh]

what they are ...could you breif me

 

[paul1598419]

I am not working with designing medical lasers, so I would not be able to give you all the governmental issues you will need to resolve without doing a search that you can easily do yourself. The laser you have shown is not a pulsed laser at all. It uses a pulse width modulation at the driver to vary the output power, but if you want a true pulsed IR laser, I would look into a Nd:YAG or a Nd:YVO4 with an optical pump. You will also need to be able to aim an invisible laser and focus it accurately. You will also need to know your power requirements for what you are attempting to do.

 

[Jirkas99]

I wouldn't use cheap module from ebay in dentist tool.. I think you will need to tell us
a little about yourself before we can give you any kind of information. It is nothing against you, we just want to know you a little bit better and also make sure that you aren't making fun of us. How old are you? What is your job? In what country do you live?

 

[navedjh]

I am not working with designing medical lasers, so I would not be able to give you all the governmental issues you will need to resolve without doing a search that you can easily do yourself. The laser you have shown is not a pulsed laser at all. It uses a pulse width modulation at the driver to vary the output power, but if you want a true pulsed IR laser, I would look into a Nd:YAG or a Nd:YVO4 with an optical pump. You will also need to be able to aim an invisible laser and focus it accurately. You will also need to know your power requirements for what you are attempting to do.

thanks for your suggestions ...but i am trying to make with GaAlAs Diode not with Nd;Yag

 

[navedjh]

I wouldn't use cheap module from ebay in dentist tool.. I think you will need to tell us
a little about yourself before we can give you any kind of information. It is nothing against you, we just want to know you a little bit better and also make sure that you aren't making fun of us. How old are you? What is your job? In what country do you live?

i am from delhi research student of biomedical engineering working on laser therapy devices

 

[paul1598419]

Building a 808nm 200 mW CW laser is quite easy to do, but it won't be pulsed, or if you pulse it, it won't have the commensurate energy that a true pulsed laser would have. That is why I suggested the Nd:YAG or Nd:YVO4 rod laser with an optical pump. You can pulse an 808nm laser diode, but it will just give you a fraction of the power you would have running it continuously.

 

[navedjh]

Building a 808nm 200 mW CW laser is quite easy to do, but it won't be pulsed, or if you pulse it, it won't have the commensurate energy that a true pulsed laser would have. That is why I suggested the Nd:YAG or Nd:YVO4 rod laser with an optical pump. You can pulse an 808nm laser diode, but it will just give you a fraction of the power you would have running it continuously.

thanks but i dont know about yag

 

[paul1598419]

YAG stands for Yttrium Aluminum Garnet and is often doped with a percent or few of Neodymium. It is optically pumped with an arc or flash lamp. If it is Q-switched, you can reduce the pulse width while increasing the output energy. You can find all this out with a google search.

 

[Cyparagon]

"Why are you pointing a cobbled-together high power laser in that guy's mouth?"
"It's okay, I'm a student, and I used the schematic from a stranger."