THORLABS APD130 Series User manual

Avalanche Photodetectors
APD130x
Operation Manual
2020

Version:
Date:
Item No.:
1.3
13-Feb-2020
M0009-510-910
Copyright © 2020 Thorlabs

Foreword
Contents 2
1 General Information 3
31.1 Safety 41.2 Ordering Codes and Accessories
2 Getting Started 5
52.1 Parts List
52.2 Preparation
3 Operating Instruction 6
63.1 Operating Principle
63.1.1 Optical Input
73.1.2 Electrical Output 83.2 Mounting
93.3 Operation
103.4 Recommendations
4 Maintenance and Service 11
5 Appendix 12
125.1 Technical Data
135.2 Typical Detector Responsivity Curves
155.3 Typical Output Frequency Response 175.4 Typical Spectral Noise
195.5 Typical M Factor Temperature Dependency
205.6 Drawings
235.7 Fiber Coupling onto Small Detector Area 245.8 Certifications and Compliances
255.9 Manufacturer Address
255.10Return of Devices
265.11Warranty 265.12Copyright and Exclusion of Liability
275.13List of Acronyms and References
285.14Thorlabs Worldwide Contacts and WEEE policy

© 2020 Thorlabs
We aim to develop and produce the best solution for your application
in the field of optical measurement technique. To help us to live up to
your expectations and constantly improve our products we need
your ideas and suggestions. Therefore, please let us know about
possible criticism or ideas. We and our international partners are
looking forward to hearing from you.
Thorlabs GmbH
Warning
Sections marked by this symbol explain dangers that might result in
personal injury or death. Always read the associated information
carefully, before performing the indicated procedure.
Please read this advice carefully!
This manual also contains "NOTES" and "HINTS" written in this form.
Attention
Paragraphs preceded by this symbol explain hazards that could
damage the instrument and the connected equipment or may cause
loss of data.
Note
2

© 2020 Thorlabs
1 General Information
3
1 General Information
The Thorlabs APD130x series of temperature-compensated Avalanche Photodetectors com-
bine a high sensitivity Si or InGaAs Avalanche Photodiode with a specially designed ultra-low
noise transimpedance amplifier for detection of optical signals from DC to 50 MHz.
APD130x series Avalanche Photodetectors have an exceptionally low NEP, making them ideal
for fast low-level light detection applications, such as spectroscopy, fluorescence measure-
ments, laser radar and optical rangefinders. Due to their very high sensitivity, the APD130x
series Avalanche Photodetectors can replace Photomultiplier Tubes (PMT) in many applica-
tions. The Avalanche Photodetectors cannot be damaged by unwanted ambient light, which is
an advantage over many photomultiplier tubes.
The APD130x series Avalanche Photodetectors are temperature-compensated. A special elec-
tronic circuit compensates the temperature dependency of the M (multiplication) factor.
The slim line housing includes a removable threaded coupler that is compatible with any of
Thorlabs 1” and ½” threaded accessories. This allows convenient mounting of external optics,
filters, apertures or fiber adapters. The APD130x has three tapped mounting holes.
The APD130x series is powered by the included external power supply LDS12B (±12 VDC, 250
mA) via a PICO M8 power connector. The appropriate input voltage (100 VAC, 120 VAC, 230
VAC) can be selected with a switch on the power supply .
1.1 Safety
Attention
The safety of any system incorporating the equipment is the responsibility of the assem-
bler of the system.
All statements regarding safety of operation and technical data in this instruction manual
will only apply when the unit is operated correctly as it was designed for.
The APD130x must not be operated in explosion endangered environments!
Do not obstruct the air ventilation slots in the housing!
Do not remove covers!
Do not open the cabinet.There are no parts serviceable by the operator inside!
This precision device is only serviceable if properly packed into the complete original
packaging including the plastic foam sleeves. If necessary, ask for replacement pack-
aging.
Refer servicing to qualified personnel!
Only with written consent from Thorlabs may changes to single components be made or
components not supplied by Thorlabs be used.
All modules must only be operated with duly shielded connection cables.
Attention
Mobile telephones, cellular phones or other radio transmitters are not to be used within
the range of three meters of this unit since the electromagnetic field intensity may then
exceed the maximum allowed disturbance values according to IEC 61326-1.
This product has been tested and found to comply with the limits according to
IEC 61326-1 for using connection cables shorter than 3 meters (9.8 feet).
5

© 2020 Thorlabs4
APD130x
1.2 Ordering Codes and Accessories
APD130C
Temperature Compensated Avalanche Photodetector, InGaAs APD,
900 - 1700 nm, 8-32 mounting holes
APD130C/M
Temperature Compensated Avalanche Photodetector, InGaAs APD,
900 - 1700 nm, M4 mounting holes
APD130A2
Temperature Compensated Avalanche Photodetector, UV-enhanced Silicon
APD, 200 - 1000 nm, 8-32 mounting holes
APD130A2/M
Temperature Compensated Avalanche Photodetector, UV-enhanced Silicon
APD, 200 - 1000 nm, M4 mounting holes
APD130A
Temperature Compensated Avalanche Photodetector, Silicon APD,
400 - 1000 nm, 8-32 mounting holes
APD130A/M
Temperature Compensated Avalanche Photodetector, Silicon APD,
400 - 1000 nm, M4 mounting holes
AC-coupled versions as well as open detector versions (detector cover glass removed) of each
model can be ordered on request.
The APD130C (/M) is factory set to M = 10.
The APD130A2 (/M) is factory set to M = 50.
The APD130A (/M) is factory set to M = 50.

© 2020 Thorlabs
2 Getting Started
5
2 Getting Started
2.1 Parts List
Inspect the shipping container for damage.
If the shipping container seems to be damaged, keep it until you have inspected the contents
and you have inspected the APD130x mechanically and electrically.
Verify that you have received the following items within the package:
1. APD130x Temperature-Compensated Avalanche Photodetector
2. SM1CP1 Metal cover cap
3. LDS12B Power Supply (±12V, 250 mA), 100 VAC, 120 VAC or 230 VAC line voltage
4. Operation manual
2.2 Preparation
Note
Prior to operation, please check if the indicated line voltage range on the power supply matches
with your local mains voltage!
Note
If you want to use your own power supply, you can ask Thorlabs for an appropriate power con-
nector cable.
·Carefully unpack the unit and accessories. If any damage is noticed, do not use the unit.
Call Thorlabs and have us replace the defective unit.
·If necessary, mount the unit on your optical table or application. The unit has three tapped
mounting holes (see section Mounting for details).
·Remove the metal cover cap that protects the optical input.
·If necessary, mount external optics, filters, apertures or fiber adapters.
·Adjust the power supply to accommodate your local mains voltage (100 VAC, 120 VAC or
230 VAC).
·Plug the power connector cable into the POWER IN.
·Plug the power supply into a outlet.
·Switch on the power supply
·Connect OUTPUT to your data acquisition device with a coaxial cable. Please note that a
50 Wimpedance device should be used for best RF performance.
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© 2020 Thorlabs6
APD130x
3 Operating Instruction
3.1 Operating Principle
The Thorlabs APD130x series of temperature-compensated Avalanche Photodetectors com-
bine a high sensitivity Si or InGaAs Avalanche Photodiode with a specially designed ultra-low
noise transimpedance amplifier for detection of optical signals from DC to 50 MHz. The buf-
fered output stage can deliver up to 1.8 V into a 50 Wimpedance load. The ultra-low noise
design includes an active low-pass filter to effectively suppress out-of-band noise. No external
high voltage power supply is required for operation.
APD130x series Avalanche Photodetectors have an exceptionally low NEP, making them ideal
for fast low-level light detection applications, such as spectroscopy, fluorescence measure-
ments, laser radar and optical rangefinders. Due to their very high sensitivity the APD130x
series Avalanche Photodetectors can replace Photomultiplier Tubes (PMT) in many applica-
tions. The Avalanche Photodetectors cannot be damaged by unwanted ambient light, which is
critical for many Photomultiplier Tubes.
Avalanche Photodiodes use an internal gain mechanism to increase the sensitivity. Incident
photons generate electron-hole pairs, like in a normal photo diode. By applying a high reverse
voltage, a strong electric field appears that accelerates these electrons and produces seconda-
ry electrons by impact ionization. This leads to an electron avalanche producing gain factors of
up to several hundreds. The amplification depends on the reverse bias voltage and is described
by the M (multiplication) factor. Due to internal processes, the M factor is temperature depend-
ent. At a fixed reverse bias voltage the M factor will change with temperature: in general, with
lower temperatures the M factor will increase, with higher temperatures - decrease.
The APD130x series Avalanche Photodetectors are temperature-compensated. A thermistor
senses the temperature inside the APD130x enclosure, and a special electronic circuit controls
the applied to the APD reverse voltage in accordance with the temperature change. As the M
(multiplication) factor depends on the applied reverse voltage, the temperature dependency of
the M factor can reduced drastically.
Please see section M Factor Temperature Dependency for typical curves.
The APD130x Series is powered by the included external power supply (±12 V, 250 mA) via a
PICO M8 power connector.
3.1.1 Optical Input
The APD130C uses an InGaAs Avalanche Photodiode with a detector active area diameter of
0.2 mm, operating from 900 to 1700 nm nm.
The APD130A uses a Silicon Avalanche Photodiode with a detector active area diameter of
1 mm, operating from 400 to 1000 nm.
The APD130A2 uses an UV-enhanced Silicon Avalanche Photodiode with a detector active
area diameter of 1 mm, operating from 200 to 1000 nm.
The typical responsivity curves can be found in the appendix .
An open beam should be carefully aligned to the detector. Additional focusing lenses can be
easily attached to the Avalanche Photodetectors. The housing is compatible with any number
of Thorlabs 1” and ½” threaded accessories. This allows convenient mounting of external op-
tics, filters, apertures or fiber adapters.
For fiber coupled applications, in case of detectors with an active area of 1 mm, fiber adapters
like Thorlabs S120-xx series can be easily mounted on the optical input. The fiber adapter will
accommodate multi-mode as well as single-mode fiber. For detectors with smaller active areas,
in order to meet specifications, it is recommended to focus the optical signal out of the fiber
onto the detector. Details please see in the appendix .
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3 Operating Instruction
7
Please note, that coupling losses may occur due to small detector size, which will result in a re-
duced output signal. If angled connectors are used the fiber adapter can be rotated from its ori-
ginal position to check for an improved alignment. For this process use an optical input power
below the saturation power while observing OUTPUT voltage on a digital voltmeter or other low-
frequency measurement device.
The maximum OUTPUT voltage swing is 3.6 V at High-Z termination. Saturation of the
OUTPUT will occur at optical input power greater than CW Saturation Power listed in specifica-
tions . If necessary, use external neutral density filters or attenuators to reduce the input light
level. Please note that the Avalanche Photodetectors are extremely sensitive to unwanted stray
light. Carefully shielding of the Avalanche Photodetectors from any unwanted light sources is
essential. Common techniques to minimize the influence of stray light include baffling or other
opaque barriers like black cloths, beam tubes or using appropriate band pass filters in front of
the detector.
Attention
The optical damage threshold is 1 mW. Exceeding this value will permanently destroy the
Avalanche Photodetector!
3.1.2 Electrical Output
Thorlabs APD130x Avalanche Photodetectors deliver an OUTPUT voltage, which is a function
of incident light power Popt, detector's responsivity ÂM(l) at a given wavelength and M factor
(see Typical Detector Responsivity Curves ), and transimpedance gain G:
·ÂM(l) for a given wavelength can be read from the spectral responsivity curves (see Tech-
nical Data ) to estimate the OUTPUT voltage.
·The M factor is factory set to 50 (APD130A, APD130A2) or 10 (APD130C) at 23°C ambient
temperature. The amplifier’s transimpedance gain Gis 100 kV/A. Please note that OUTPUT
voltage is reduced by a factor of 0.5 if connected to a 50 Wload.
The maximum output voltage swing of OUTPUT is 3.6 V for high impedance loads (1.8 V into
50 W). Depending on the wavelength responsivity Â(l)of the detector and the M factor, the
amplifier will reach saturation at optical input power greater than CW Saturation Power listed in
specifications. To avoid saturation, keep the output signal below the specified maximum output
voltage.
The output of the APD130x Avalanche Photodetectors is a BNC connector.
The amplifier offset voltage is factory set to zero at 23°C ambient temperature. Due to the very
high transimpedance gain, small temperature changes may affect offset voltage. Therefore it is
recommended to use the Avalanche Photodetectors in a constant temperature environment
after a short warm up period (~5 min) for exact DC light level measurements.
In the appendix, typical curves for Output Frequency Response , Spectral Noise Distribu-
tion and M Factor Temperature Dependency can be found.
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© 2020 Thorlabs8
APD130x
3.2 Mounting
The APD130x series is housed in a rugged 2 x 2.5 x 1 inch shielded aluminum enclosure. The
slim line housing comes with a removable threaded coupler that is compatible with any number
of Thorlabs 1” and ½” threaded accessories. This allows convenient mounting of external op-
tics, filters, apertures or fiber adapters, as well as providing an easy mounting mechanism using
the Thorlabs cage assembly accessories. The electrical connectors and the ON/OFF switch are
conveniently located on the side walls of the housing for easy access and to minimize the thick-
ness of the Avalanche Photodetector so it can fit into tight spaces. For maximum flexibility the
APD130x has three 8-32 (M4 for metric version) tapped mounting holes to mount the unit to a
post or pedestal.

© 2020 Thorlabs
3 Operating Instruction
9
3.3 Operation
·Turn the power switch to I. The green LED on the APD130x indicates correct power sup-
ply.
·Adjust the optical source to the optical input. The maximum OUTPUT voltage swing is 3.6
V for high impedance loads (1.8 V into 50 Wloads). The output signal must not exceed
this maximum output voltage to avoid saturation. External neutral density filters or attenu-
ators are recommended to reduce the input light level in critical cases.
·Turn the power switch to Owhen you are finished the measurements.
Note
Avoid saturating the amplifier! Therefore, make sure that the optical input power does not ex-
ceed the saturation power level listed in specifications .
Attention
Exceeding the optical damage threshold input power will permanently destroy the detector!
12

© 2020 Thorlabs10
APD130x
3.4 Recommendations
Please always remember that the Avalanche Photodetectors are extremely sensitive devices.
Carefully shielding the Avalanche Photodetectors from any unwanted light sources is essential.
Common techniques include baffling or other opaque barriers like black cloths or lens tubes.
It is highly recommended to use appropriate band pass filters in front of the detector to mini-
mize the influence of stray light.
Since stray light has its strongest frequencies at DC and line frequency or harmonics, optical
chopping and Lock-In detection can further improve measurement sensitivity.
It is not necessary to switch off the Avalanche Photodetectors when it is exposed to ambient
light. The amplifier will saturate but unlike Photomultiplier Tubes it will not be damaged or satu-
rated for a long period of time.
Another critical point can be electrostatic coupling of electrical noise associated with ground
loops. In most cases an electrically isolated post (see Thorlabs parts TRE or TRE/M) will sup-
press electrical noise coupling. You should always try to identify the electrical noise sources
and increase the distance to the Avalanche Photodetector. If possible, you can also rotate the
Avalanche Photodetector input away from the noise source. Different common ground points
can also be tested.
The amplifier offset voltage is factory set to zero at 23°C ambient temperature. Due to the
very high transimpedance gain, even small temperature changes may affect offset voltage.
Therefore it is recommended to use the Avalanche Photodetector in a constant temperature
environment after a short warm up period (~5min) for exact DC light level measurements.
The M factor is factory set at 23°C ambient temperature. The APD130x are operated at an in-
ternal reverse bias voltage that is temperature-compensated, and their actual M factor will re-
main nearly constant within the specified ambient temperature range of (23±5) °C.

© 2020 Thorlabs
4 Maintenance and Service
11
4 Maintenance and Service
Protect the APD130x from adverse weather conditions. The APD130x is not water resistant.
Attention
To avoid damage to the instrument, do not expose it to spray, liquids or solvents!
The unit does not need a regular maintenance by the user. It does not contain any modules
and/or components that could be repaired by the user himself. If a malfunction occurs, please
contact Thorlabs for return instructions.
Do not remove covers! High voltage!

© 2020 Thorlabs12
APD130x
5 Appendix
5.1 Technical Data
APD130C
APD130A
APD130A2
Parameter
Detector Material/Type
InGaAs APD
Silicon APD
UV-enhanced Silicon
APD
Wavelength Range
900 to 1700 nm
400 to 1000 nm
200 to 1000 nm
Maximum APD Responsivity
9 A/W
@ 1500 nm, M = 10
25 A/W
@ 800 nm, M = 50
25 A/W
@ 600 nm, M = 50
M Factor Temperature Stabil-
ity 1)
typ. ± 2 %; max. ± 3 %
Detector Active Area Diameter
0.2 mm
1 mm
1 mm
Transimpedance Gain
100 kV/A
50 kV/A with 50 Wter-
mination
100 kV/A
50 kV/A with 50 Wter-
mination
100 kV/A
50 kV/A with 50 Wter-
mination
Maximum Conversion Gain
0.9 x 106V/W
2.5 x 106 V/W
2.5 x 106 V/W
OUTPUT Bandwidth (3 dB)
DC to 50 MHz
DC to 50 MHz
DC to 50 MHz
CW Saturation Power
4.2 µW
1.5 µW
1.5 µW
Maximum Input Power
(Photodiode Damage
Threshold)
1 mW
1 mW
1 mW
Minimum NEP (DC - 50 MHz)
Integrated Noise (DC - 50
MHz)
3.3 nW (RMS)
1.4 nW (RMS)
1.5 nW (RMS)
Electrical Output, Impedance
BNC, 50 W
Maximum Output Voltage
3.6 V (High Z load)
1.8 V (50 W)
DC-Offset Electrical Output
< ±15 mV
Power Supply
±12 V, 250 mA (100 V,120 V,230 V switchable)
General
Operating Temperature Range
2)
0 - 40 °C
Storage Temperature Range
-40 to 70 °C
Dimensions (W x H x D)
2 x 2.5 x 1" (50.8 x 63.5 x 25.4 mm3)
Weight
< 0.1 kg
1) Ambient temperature within (23 ± 5)°C
2) Non-condensing
All technical data are valid at (23 ± 5) °C and (45 ± 15) % rel. humidity (non condensing)

© 2020 Thorlabs
5 Appendix
13
5.2 Typical Detector Responsivity Curves
Typical Detector Responsivity APD130C; M = 10
Typical Detector Responsivity APD130A; M = 50

© 2020 Thorlabs14
APD130x
Typical Detector Responsivity APD130A2; M = 50

© 2020 Thorlabs
5 Appendix
15
5.3 Typical Output Frequency Response
For this measurement a test signal, generated by an optical transmitter, was fiber-coupled to
the Avalanche Photodetector. The OUTPUT frequency response was measured using a optical
network analyzer.
Typical Output Frequency Response APD130C
Typical Output Frequency Response APD130A

© 2020 Thorlabs16
APD130x
Typical Output Frequency Response APD130A2

© 2020 Thorlabs
5 Appendix
17
5.4 Typical Spectral Noise
The typical noise spectrum was measured using an electrical spectrum analyzer (resolution
bandwidth 10 kHz, video bandwidth 10 kHz). The optical input of the detector was blocked. The
black curve ("Reference") was measured with the same setup and the detector switched off ,
i.e., it represents the measurement system’s noise floor.
Typical Spectral Noise APD130C
Typical Spectral Noise APD130A

© 2020 Thorlabs18
APD130x
Typical Spectral Noise APD130A2