TERA OSCAT0 pages
TERA OSCAT
ALL-FIBER THz
SPECTROMETER FOR
RAPID SCAN
APPLICATIONS
APPLICATION EXAMPLE
Rapid measurements of a graphite film in a pulsed magnetic field
magnetic field
THz-field
Amplitude (a.u.)
1
Our new all-fiber THz spectrometer for
0.5
0
-0.5
fast data aquisition is based on the novel
OSCAT
(Optical
Sampling
by
-1
CAvity
0.00
Tuning) technique. It enables THz timedomain spectroscopy without any moving
Hi
g
wi me h S
th as pe
ou u ed
t d re m T
D
el
ay ent lin s
e
0.01
0.02
0.03
Time (s)
PRINCIPLE OF OPERATION
parts. Combined with our TERA Image
Similar to the ASOPS technique, the OSCAT
measurements.
TERA OSCAT is a robust and portable
solution for both laboratory use and OEM
integration, suitable even for harsh industrial environment.
TERA OSCAT - OPTICAL UNIT
OSCAT TERA Image
∆τ
target
i-3
...
i-3
i-2
i-2
i-4
i-5
...
BS
M
offers great flexibility in system configuration and capability of high-speed
0.05
i-1
i
pulse
source
ld, td
for fast THz imaging applications.
i
i-1
extension, the system provides a solution
0.04
lp,tp
In the novel OSCAT technique there is no need for an external moveable delay line.
Contrary to the conventional THz-TDS systems, the lengths of the emitter and
detector arms are not balanced. The temporal shift ∆τ between the pulses i (emitter
arm) and i + a (detector arm) is determined by the repetition rate frep of the fs
laser.
1
1
∆τ = a
−
f
f rep + ∆f
rep
For further details see T. Hochrein et. al in "Optical sampling by laser cavity tuning,"
Opt. Express 18, 1613-1617 (2010).
SYSTEM LAYOUT
SYSTEM LAYOUT
control
electronics
ber laser
port A
port B
ber delay line
3m
3m
Rx, LT-InGaAs
Tx, LT-InGaAs
Y
µA
X
TERA Image
(optional)
PC with
data acquisition