Hamamatsu News 2-2014 - page 11

OPTO-SEMICONDUCTOR PRODUCTS
11
News 2014 Vol. 2
Balanced Detector
C12668-01/-02
NEW
Academic Res.
ND Inspection
Industry
Security
Optical Comms
Semicon Prod.
Analytical
Measurement
Drug Discovery
Life Science
Medical
Specifications
Parameter
C12668-01 C12668-02
Unit
Photodiode incorporated
InGaAs PIN photodiode
-
Wavelength
1.0
1.3
μm
Frequency response range
DC to 200
MHz
CMRR
35
dB
Trans-impedance gain
3 x 10
4
V/A
Output impedance
50
Ω
Input section
FC receptacle (APC polished)
-
Output section
SMA receptacle
-
Supply voltage
±12 (200 mA)
V
Dimensions
65 x 75 x 25
mm
Balanced detectors that minimize multiple reflections
The C12668-01 and C12668-02 are differential amplification type photo­
electric conversion modules containing two photodiodes developed in-house
having well-matched characteristics. The photodiodes are connected in a
direction that cancels out the photocurrent of each photodiode and the
common mode noise of the two incident light rays. The minute difference
in light level is treated as a displacement signal which is converted into an
electrical signal and output.
These balanced detectors are suitable for OCT (optical coherence tomography)
used for ophthalmic diagnosis and the like (see “Ophthalmic diagnosis
image”).
The tiny differences in signal light that are generated when backscatter light
from a subject interferes with reference light can be converted into electrical
signals with these balanced detectors.
Features
„
„
Employs our unique structure that reduces multiple reflections at the
incident light wavelength of 1.0 μm or 1.3 μm
„
„
Cutoff frequency: 200 MHz
„
„
CMRR (Common-Mode Rejection Ratio): 35 dB
Application
„
„
OCT
C12668-01, C12668-02
Eye
Interference mirror
Optical coherence
tomography
Wavelength-swept
light source
DAQ interface
+
PC
Balanced detector
Reference
light mirror
Ophthalmic diagnosis image
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