Datasheet - Hamamatsu

Balanced detectors
C12668 series
Balanced detectors with reduced multiple reflections
These are differential amplification type photoelectric conversion modules containing two Hamamatsu photodiodes with balanced characteristics. The photodiodes are connected in a direction that cancels out the photocurrent of each photodiode.
This configuration cancels out the common mode noise of the two incident light rays. The minute difference in light levels is
treated as a displacement signal, converted into an electrical signal, and output. Moreover, the adoption of our unique structure that suppresses multiple reflections of incident light has made it possible to reduce the noise caused by the reflections.
These products can be applied to optical coherence tomography (OCT) used in ophthalmologic examinations and the like. The
balanced detector can convert into electrical signals the minute difference in the signal light produced when the back scattering light from the subject is made to interfere with the reference light.
Features
Application
Employs our unique structure that reduces multiple reflections
at the incident light wavelength of 1.0 μm or 1.3 μm
OCT
Cutoff frequency: 200 MHz
Common-mode rejection ratio (CMRR): 35 dB typ.
Input section: FC receptacle (APC polished)
A single-mode fiber with an FC connector can be connected.
Output section: SMA receptacle
Compact
Structure
Parameter
Built-in element
Dimensions
Weight
Input section
Output section
Specification
InGaAs PIN photodiode
65 × 75 × 25
168
FC receptacle (APC polished)
SMA receptacle
Unit
mm
g
-
Absolute maximum ratings
Parameter
Supply voltage
Operating temperature*1
Storage temperature*1
Symbol
Vs
Topr
Tstg
Condition
Ta=25 °C
Value
±17
0 to +50
-10 to +60
Unit
V
°C
°C
*1: No condensation
Note: Exceeding the absolute maximum ratings even momentarily may cause a drop in product quality. Always be sure to use the
product within the absolute maximum ratings.
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1
Balanced detectors
C12668 series
Electrical characteristics (Ta=25 °C, unless otherwise noted)
Parameter
Supply voltage*2
Current consumption
Symbol
Vs
Ic
Output impedance
Zo
Condition
±12 V
±12 V, dark state
OUT terminal
Monitor terminal
Min.
±11
±52
-
Typ.
±12
±60
50
220
Max.
±13
±64
-
Unit
V
mA
Ω
*2: Use a power supply with at least 200 mA output.
Electrical and optical characteristics (Typ. Ta=25 °C, unless otherwise noted)
Parameter
Optimal wavelength band*3
Photosensitivity
Symbol
λo
SPD
Frequency bandwidth
fb
CMRR
Common-mode rejection ratio*4
Transimpedance gain
Zt
Output noise voltage
Vn
Condition
Optimal wavelength
-3 dB, OUT terminal
-3 dB, Monitor terminal
OUT terminal
OUT terminal
Monitor terminal
Dark state,
50 Ω termination,
OUT terminal
C12668-01
1.0
0.75
C12668-02
1.3
0.95
DC to 200
DC to 0.1
35
3 × 104
1 × 104
40 max.
Unit
μm
A/W
MHz
dB
V/A
V/A
mVp-p
*3: Wavelength band in which multiple reflections can be reduced the most
*4: Output difference when an approximately 70 μW light is applied to only the INPUT- terminal and when applied to INPUT+ and
INPUT- terminals (see the frequency characteristics)
Frequency characteristics (typical example)
(Ta=25 °C)
60
50
Output (dB)
40
Applied only to
INPUT- terminal
Applied to INPUT+
and INPUT- terminals
30
CMRR
20
10
0
-10
0.01
0.1
1
10
100
1000
Frequency (MHz)
KACCB0358EA
2
Balanced detectors
C12668 series
Block diagram
Amplifier
Mon-
INPUT-
Amplifier
I/V amplifier
OUT
INPUT+
Amplifier
Mon+
KACCC0761EA
Dimensional outline (unit: mm)
54.5
(15)
P.S.
±12 V
(9.5) (14)
Mon.-
INPUT(FC/APC)
(28.5)
65
OUT
(15)
INPUT+
(FC/APC)
(20)
(10.5)
Mon.+
(7.5)
(11)
(8.5)
(11)
M4 indication
10
M4 depth 6
11
(24)
14
No8-32UNC depth 6
Tolerance unless otherwise noted: ±0.3
KACCA0351EA
3
Balanced detectors
C12668 series
Accessory (unit: mm)
Cable for power supply (no connector on one end)
4
(ɸ9.8)
3
RKMV 3-224/2M
(LUMBERG AUTOMATION, 3-pin, female)
(8.2)
(27)
Pin no.
1
3
4
(15)
(4.3)
1
(2000)
Wire color
Brown (+12 V)
Blue (-12 V)
Black (GND)
KACCA0352EA
Connection example (ophthalmic medical OCT)
OCT
Mirror for reference light
Wavelength swept
light source
Eyeball
Interference light
DAQ interface + PC
Balanced
Balanced
dd
detector
KACCC0762EA
4
Balanced detector
C12668 series
Related information
www.hamamatsu.com/sp/ssd/doc_en.html
Precautions
· Disclaimer
Information described in this material is current as of February, 2015.
Product specifications are subject to change without prior notice due to improvements or other reasons. This document has been carefully prepared and the
information contained is believed to be accurate. In rare cases, however, there may be inaccuracies such as text errors. Before using these products, always
contact us for the delivery specification sheet to check the latest specifications.
Type numbers of products listed in the delivery specification sheets or supplied as samples may have a suffix "(X)" which means preliminary specifications or
a suffix "(Z)" which means developmental specifications.
The product warranty is valid for one year after delivery and is limited to product repair or replacement for defects discovered and reported to us within that
one year period. However, even if within the warranty period we accept absolutely no liability for any loss caused by natural disasters or improper product
use.
Copying or reprinting the contents described in this material in whole or in part is prohibited without our prior permission.
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HAMAMATSU PHOTONICS K.K., Solid State Division
1126-1 Ichino-cho, Higashi-ku, Hamamatsu City, 435-8558 Japan, Telephone: (81) 53-434-3311, Fax: (81) 53-434-5184
U.S.A.: Hamamatsu Corporation: 360 Foothill Road, Bridgewater, N.J. 08807, U.S.A., Telephone: (1) 908-231-0960, Fax: (1) 908-231-1218
Germany: Hamamatsu Photonics Deutschland GmbH: Arzbergerstr. 10, D-82211 Herrsching am Ammersee, Germany, Telephone: (49) 8152-375-0, Fax: (49) 8152-265-8
France: Hamamatsu Photonics France S.A.R.L.: 19, Rue du Saule Trapu, Parc du Moulin de Massy, 91882 Massy Cedex, France, Telephone: 33-(1) 69 53 71 00, Fax: 33-(1) 69 53 71 10
United Kingdom: Hamamatsu Photonics UK Limited: 2 Howard Court, 10 Tewin Road, Welwyn Garden City, Hertfordshire AL7 1BW, United Kingdom, Telephone: (44) 1707-294888, Fax: (44) 1707-325777
North Europe: Hamamatsu Photonics Norden AB: Torshamnsgatan 35 16440 Kista, Sweden, Telephone: (46) 8-509-031-00, Fax: (46) 8-509-031-01
Italy: Hamamatsu Photonics Italia S.r.l.: Strada della Moia, 1 int. 6, 20020 Arese (Milano), Italy, Telephone: (39) 02-93581733, Fax: (39) 02-93581741
China: Hamamatsu Photonics (China) Co., Ltd.: B1201, Jiaming Center, No.27 Dongsanhuan Beilu, Chaoyang District, Beijing 100020, China, Telephone: (86) 10-6586-6006, Fax: (86) 10-6586-2866
Cat. No. KACC1219E01 Feb. 2015 DN
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