Gooch & Housego FIBER-Q User manual

FIBER COUPLED AOM US
ER MANUAL
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PEC 0205 Issue 1
As part of our poli y of ontinuous produ t improvement, we reserve the right to hange spe ifi ations at any time.
May 2017
Page
1
F
IBER
COUPLED AOM USER MANUAL
FIBER-Q®
APPLICATION NOTE
This short do ument provides some basi information on using and the G&H Fiber-Q®. Should
you need further details please onta t us and we will be happy to help.
Basic Principle:
A radio frequen y (RF) signal applied to the piezoele tri transdu er generates a travelling
a ousti wave in the bulk material. This a ousti wave produ es a refra tive index ‘grating’.
In ident light is diffra ted from this grating.
The amplitude (intensity) of this diffra ted light may be ontrolled by adjusting the applied RF
power.
The a ousto-opti intera tion also generates an inherent frequen y shift (Doppler Effe t), su h
that the diffra ted light has frequen y = in ident light + RF drive frequen y as indi ated in the
diagram.
Acoustic
Transducer
Acoustic
W
aves
Carrier Frequency f
Diffraction order
(frequency F + f)
Input light
(Frequency F)
order (Frequency F)

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FIBER COUPLED AOM US
ER MANUAL
...............................................
.........................................................................................................................
........
PEC 0205 Issue 1
As part of our poli y of ontinuous produ t improvement, we reserve the right to hange spe ifi ations at any time.
May 201
7
Page
2
Operation Scheme:
To use a fiber oupled a ousto-opti modulator (AOM), onne t the two fiber ports (re ipro al)
into the light path, then onne t the driver to the AOM SMA onne tor using a suitable RF able.
Adjust the RF power level to optimise throughput (minimise insertion loss), taking great are not
to ex eed the maximum re ommended RF power (as indi ated in the spe ifi ations).
The diffra ted light may be modulated via the analogue or digital modulation input on the RF
driver.
Heat Sinking Fiber Coupled AOM
The stability of our fiber oupled AOM depends on effi ient internal heat ondu tion. For long
term use we re ommend heat sinking the base of Fiber-Q® pa kage housing as des ribed in the
figure below.
In order to aid thermal ondu tion, it is ne essary that thermal onta t is ensured at the onta t
surfa e between Fiber-Q® housing and the heat sink. To a hieve this please;
•
Use a thermally ondu tive interfa e layer; su h as paste tape, or other interfa e
materials (there are an extensive range of ommer ially available produ ts).
•
Bolt down the devi e to the heat sink through the four fixing holes on the pa kage. M2 x
10 so ket head ap s rews are re ommended for fixing the hermeti Fiber-Q®,
re ommended torque for fixing to a steel surfa e is 0.1 Nm.

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FIBER COUPLED AOM US
ER MANUAL
...............................................
.........................................................................................................................
........
PEC 0205 Issue 1
As part of our poli y of ontinuous produ t improvement, we reserve the right to hange spe ifi ations at any time.
May 201
7
Page
3
During operation, it is inevitable, that over time the temperature of the heat sink may rise
ex essively if passive onve tion from the heat sink to its environment does not effi iently dump
ex ess heat. Ways to ombat this in lude fans and fins to aid onve tion, or water ooling.
Certainly, a temperature probe on the heat sink during operation will show whether a tive heat
sinking is ne essary.