CTI PCAOM specifications, V50

I have an optical sled from a Melles Griot multi-wavelength light source; as well as a very nice 561nm laser, it has a PCAOM on the sled; the PCAOM is marked as a CTI V-50; I guess this is a Melles Griot OEM part number as it's not on the Gooch and Housego site or in any of CTI's old catalogues. Does anyone happen to know the specs for this PCAOM? It's similar to a number of other CTI / G&H designs and has an SMA RF connector along with a 4 pin connector that appears to be for a temperature sensor.

Worse comes to worse, you can send it to me and I can sweep it on the bench, I have the needed programmable RF generators, reflectometer, and RF amp...
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First thing to do is sweep it looking for the region where the matching network reflects the least RF, using no more then say 10 mW of RF.... Then comes the tricky part.. Just having a VNA setup does not guarantee you'll hit the sweet spot on the RF... Then it gets aligned with an Argon and adjusted for peak laser with minimum RF. Make sure you mark the orientation of the crystal relative to the Brewster windows on the MG, hopefully there were no mirrors between the laser and the crystal to rotate the polarization. Yes, they are very polarization sensitive.,. If I remember right CTI made them using channel bands anywhere from 40 to 170 Mhz...
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Gooch and Housego bought the corporate remains, so I'm told, as Siemens only wanted the Lithium Niobate side of the business... You can ask there...
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Keep in mind, its a multi-channel AOTF to non-laserists...
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You don't need the exact frequencies, unless your using crystal oscillators as the sources, or looking for a factory driver... You just need to determine the band the RF matching network is tuned for. With programmable frequency sources, you just need N PLLs or DDS boards, N doubly balanced mixers as modulators, and a wideband RF amp...

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Steve

Cheers Steve. As an ex RF engineer I should really have thought of that. I pinged an email to G&H, but not really expecting a reply.
I'll have to see if I can borrow some of the test gear in one of our labs at work.

One to eight channels...
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Typically the chain is
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DDS, Crystal Oscillator, or PLL > Isolation MMIC AMP > DBM for Modulation > booster MMIC amp > Passive Combiner > CATV Hybrid Power Amplifier
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For a NEOS, manual says DO NOT EXCEED MORE THEN 125 mW per Color Channel of RF.. I seem to remember CTI using no more then 70 mW per channel, but it's been ten years since I looked at their specs.
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Tuning in 30 KHz steps is fine, if needed, I have both crystal fixed and PLL tunable drivers. A typical RF carrier gets you four nanometers of optical bandwidth, so you can afford to miss a bit on the carrier frequency. . The PLL tuning lets you peak the throughput nicely, but is not often needed..
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There is a sweet spot optically, one place that is just the right distance in the crystal from the transducers to have a hot spot. Modulation will occur across the crystal, but there is one, maybe two places where really sweet efficiency happens across 1 mm^2 or so of crystal. Keep that in mind when bench testing.
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I used to be stuck with a fixed frequency, four channel, crystal based driver. One day I started to build an eight channel driver using "one time programmable" crystal oscillators with built in VHF PLLs from CTS Crystals... At 13$ per channel that was not bad. The next week I was offered a 8 PLL based tunable driver for my NEOS at a price I could not refuse. So if you can find a set of frequencies you like, I'll sell you my 10 channel MiniCircuits RF splitter/combiner at the cost I paid on Fleabay...
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Bench Trick of the Day.. Take a desk lamp with a tungsten bulb, and take the lampshade off, so you have a bare bulb.. Place it a few meters away from the PCAOM at eye level. With the RF on, look at the lamp thru the PCAOM and tilt the crystal around by eye. If your close on the RF and find a nearby angle, you'll see a monochromatic image of the bulb in some color...
LED and Compact Fluro bulbs have big gaps in their white spectrum. So I like tungsten or metal halide for this.
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Blinking the RF on/off/on at 1-2 Hz really helps in initial alignment.
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Steve

Cheers Steve, that's very helpful. I have some synthesized AOM drivers that were destined for a works project, but they ended up going down a cheaper route; I'm going to take a look to see how easy they would be to modify to get the required frequencies, once I know what they are.

Well G&H came up trumps and identified it, it's a variant of their standard 97-02838 AOTF and I have tha data sheet now.

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Originally Posted by NobleGas

Well G&H came up trumps and identified it, it's a variant of their standard 97-02838 AOTF and I have tha data sheet now.

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G&H has an old school policy of being damn helpful when they can. As well as a policy of keeping a test sheet on everything they have every sold, for as long as possible.
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Let me know if you want the RF combiner... I wont be using it any time soon...
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These worked for me, and Digikey programmed them for me prior to shipment.
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http://www.digikey.com/product-detai...8PIN-ND/502289
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Glad this is working out for you. 80-150 Mhz is not that bad for making a driver..
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Steve