ISOMET RFA920T Series, Руководство пользователя

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10
ISOMET
Schematic of a basic acousto optic deflector
and tunable driver
RF
1st Order Scan
0th Order
Input Laser Beam
Intensity Modulation
Tuning Voltage



SEP
SCAN
BRAGG
AO Deflector
Deflector Driver
The input Bragg angle, relative to a normal to the optical surface and in the plane of deflection is
given by:
 

BRAGG
=

fc
2.v
The separation angle between the zeroth order and mid scan point of the first order is given by:
    

SEP
=

fc
v
The first order scan angle is given by:
    

SCAN

=

f
v
The access time or time aperture is given by:
T
acc
= d/v
where :

= wavelength
 
f = scan frequency bandwidth
fc = centre frequency
v = acoustic velocity of the crystal material
Quartz 5.7mm/usec
Germanium 5.5mm /usec
d = beam diameter
Figure 4: Deflector Parameters