writing a long period grating

Hallo friends,

I bother you for help.

I am trying to write a LPG into a photosensitive fiber type Nufern GF1 by point to point technique (i.e. I am using a shutter to block the beam and making a pattern with period 400um). I have used a power of

50mW and the beam is focused into a spot of 200um, the exposure time is 3min per cell, 60 cells . The result is: nothing!

Does anybody have an idea about what I do wrong?

I have some dubts already, but I am not sure whether they are correct or not:

1) the photosensitivity is still too low and I will never get anything with this laser (I cannot send in more power) 2) I do not make beam filtering to avoid the waste of power. Does this limit the focusing due to abberations?

Thanks in advance to anybody who can give me some hints!

Asnass

Reply to
asnass
Loading thread data ...

Cabling-Design.com Forums website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.