very high collimated lens.

[hiren_dave]

Hi,

I want to design a project named "high range laser distance finder". Here, my laser is not collimated and its spread. So i want highly collimated lens that can maintain laser beam to infinite range.

is it possible? or it must maintain laser beam up to 1 km.

 

[keith1200rs]

The exact choice of lens depends on the laser. Are you using a high power 905nm pulsed laser? If so, which one? You will end up with a spot size at 1km which depends on the laser stripe size and the focal length of the lens. "infinite" is not really practical.

Keith.

 

[hiren_dave]

thanks keith...

actually i have not decided for laser. help me to decide pulsed laser which can maintain it's spot size up to 1 Km.

 

[keith1200rs]

I would suggest you look at the Osram ones

The higher ower ones (e.g. 70W) tend to be multiple stacked lasers, usually three. That means the imaged spot will be 3 stripes, one above the other. The smaller power lasers, e.g 10W will be single lasers. They can be quite wide so you need to calculate the focal length of the lens to take that into account - the strip size at 1km will be quite large without some fancy optics. If you can live with a large stripe at 1km then a simple lens will do.

You need a large aperture lens otherwise you will lose a lot of the light.

Some lasers can be bought with built in drive transistors - I would recommend those as it makes the design easier.

You could look at Perkin Elmer https://www.perkinelmer.com/CMSReso...laserdiodefamilyforindustrialrangefinding.pdf They bought out EG&G laser and photodiode division, I seem to recall.

I don't know if you are also looking at avalanche photodiodes as well, but if so, EG&G do those, as do Hamamatsu.

Keith.

 

[hiren_dave]

Thanks keith...............