Laser Pointer Measurement

[chad]

Yeah, that thing is cool. How about a picture of her with her nickers off?

chad

[masterpj]

hehe sorry for that before, i read to quick and read pointer without realising it was about the wavelength.
Really sorry.
anyway yeah I'm also curious what's going on inside that box.

[-bart-]

Never thought a pointer could be stable at half a Gigahertz

[Eidetic]

No harm, no foul, no worries!

[mixedgas]

MasterPJ, the reason his post about measurement is valid is so I can say...

Hey, can you take a picture of that weird "unobtainium" fiber connector they use? That way I can fix my friend's Burleigh... Note, if the light does not come in from a fiber, the wavelength readout shifts like mad.

I could also use the fiber core/cladding numbers.

It was some connector that never caught on in the commercial market!

Thanks, Steve

[Banthai]

Booming ding dongs .....

is That Steve asking for Advice .... well you are human like us after all ... i Just thought you only helped other people

all the best buddy and hope you get the Burleigh fixed .....

Eidtic..... that Burleigh you have looks a loverly bit of tech....

all the best ....

Karl

[flecom]

Never thought a pointer could be stable at half a Gigahertz

thats a wavelength meter not a frequency counter

[krazer]

The old WA-10 and WA-15 were not fiber coupled, and only had the free space input. The newer 1000/1500 models have the fiber coupled input (along with temperature/pressure compensation and more advanced electronics to allow lasers with a wider spectral width to be measured), usually with a FC-APC or FC-PC connector. That is pretty standard telecom stuff, just make sure remember that fibers with a green stress relief is APC and ones with a blue stress relief are PC. If it isn't green or blue, it is probably PC, but you can double check by looking at it and checking the tip is cut at an angle. Pretty much all multimode fibers are flat (FC-PC)

Regardless, the free space input is really not that picky about alignment (its way better than something like a fiber coupler), you just set the test laser a foot or two away from the meter, and align it so that the red tracer beam from the wavemeter is incident on the laser aperture. Then aim the laser (using some kind of kinematic mount preferably) into the instrument, and viola. If you have a modern one with the power meter you can peak for max power, but that isn't really necessary as long as you get a reading. I suspect that your issue with the readings jumping around were due to the laser just not being very stable, if you try to measure the spectrum of a multimode diode (like a 445nm or the likes) it will be very unhappy since it can't keep up with the mode hops.

@flecom - While it doesn't actually 'count' the frequency directly it does act as a frequency counter, you can even set the modern ones to give you the frequency of the laser in GHz if you want ;-) Just keep in mind that all you need to convert wavelength into frequency is the speed of light.

[flecom]

@flecom - While it doesn't actually 'count' the frequency directly it does act as a frequency counter, you can even set the modern ones to give you the frequency of the laser in GHz if you want ;-) Just keep in mind that all you need to convert wavelength into frequency is the speed of light.

ah I guess, I didn't really think of it like that... I've got most of it covered as my friends say "from DC to light" lol

[142laser]

The pointer must have "reasonable" coherence. The WA 2500 Wavemeter will not measure many diode lasers as the linewiidtha are too broad. The spec is 150 GHz or 5/cm. The higher resolution WA 20 models only go up to 20 GHz so the WA 2500 is actually a better choice; who really needs picometer resulutuon anyway? Phil, 142laser

PS I have a WA 2500 in my lab also Bob; they are easy th use and nice.