THORLABS PDF10 Series User manual

Femtowatt Photoreceiver
PDF10x
Operation Manual
2018

Copyright © 2018 Thorlabs
Version:
Date: 1.3 05-Dec-2018

Foreword
Contents
2
1 General Information 3
31.1 Safety
41.2 Ordering Codes and Accessories
2 Setting Up 5
52.1 Parts List
52.2 Getting Started
3 Operating Instruction 6
63.1 General Principle of Operation
73.2 Operating Elements
83.3 Properties and specifications
83.4 Mounting the PDF10x Series
4 Maintenance and Service 10
104.1 Recommendations
5 Appendix 11
115.1 Technical Data
125.1.1 PDF10A
145.1.2 PDF10C
165.2 Dimensions
175.3 Certifications and Compliances
185.4 Warranty
185.5 Exclusion of Reliability and Copyright
195.6 Thorlabs 'End of Life' Policy (WEEE)
205.7 Thorlabs Worldwide Contacts

© 2018 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
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© 2018 Thorlabs
1 General Information
3
1 General Information
The Thorlabs PDF10x series Femtowatt Photoreceivers combines a very low noise Silicon or
InGaAs photodiode with a specially designed ultra low noise transimpedance amplifier with ex-
tremely high gain of up to 1012V/A. This unique combination results in a Photoreceiver with
femtowatt sensitivity due to its exceptional low NEP, making them ideal for low-light level detec-
tion applications, such as spectroscopy and fluorescence measurements. Direct detection of
optical power down to ~10 fW is possible; in combination with an optional Lock-In Amplifier
even sub-femtowatt sensitivity can be achieved.
Due to a very high sensitivity the PDF10x Femtowatt Photoreceivers can replace photomulti-
plier tubes (PMT´s), avalanche photodiodes (APD´s) and liquid nitrogen cooled germanium
photodiodes in many applications. No expensive high voltage power supply or cooling is re-
quired.
The PDF10x cannot be damaged by unwanted ambient light, which is critical for many pho-
tomultiplier tubes.
The new slim line housing includes a removable threaded coupler that is compatible with a
number of Thorlabs 1” and ½” threaded accessories. This allows convenient mounting of ex-
ternal optics, filters, apertures or fiber adapters, as well as providing an easy mounting mechan-
ism using the Thorlabs cage assembly accessories. The PDF10x has three tapped mounting
holes and includes an external power supply.
The “Getting Started ” section below gives an overview of how to set up the PDF10x series
Femtowatt Photoreceivers. Subsequent sections contain detailed information about principle of
operation, operating suggestions and technical specifications.
1.1 Safety
Attention
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.
Before connecting the power supply to the mains make sure that the line voltage range
marked on the power supply agrees with your local supply.
The unit must not be operated in explosion endangered environments!
All modules must only be operated with proper shielded connection cables.
Only with written consent from Thorlabs may changes to single components be carried
out or components not supplied by Thorlabs be used.
This precision device is only serviceable if properly packed into the complete original
packaging including the plastic foam sleeves. If necessary, ask for a replacement pack-
age.
Mobile telephones, handy 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 EN 50 082-1.
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© 2018 Thorlabs4
PDF10x
1.2 Ordering Codes and Accessories
The following models of PDF10x series are available:
PDF10A Femtowatt Photoreceiver, Silicon detector, 320 - 1100nm
PDF10C Femtowatt Photoreceiver, InGaAs detector, 800 - 1700nm
Accessories
S120-FC FC/PC Fiber Adapter Cap with Internal SM1 (1.035"-40) Thread
S120-SMA SMA Fiber Adapter Cap with Internal SM1 (1.035"-40) Thread
In general, all Thorlabs internal SM1 (1.035"-40) and external SM05 (0.535"-40) threaded ac-
cessories are compatible with the PDF10x. Please refer to www.thorlabs.com for further inform-
ation.

© 2018 Thorlabs
2 Setting Up
5
2 Setting Up
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 PDF10x mechanically and electrically.
Verify that you have received the following items within the package:
1. PDF10x Femtowatt Photoreceiver
2. SM1T1 SM1 Coupler (internal thread)
3. Metal cover cap
4. LDS12B power supply (±12V, 250 mA), 100 V, 120 V, or 230 V line voltage
5. Operation manual
2.2 Getting Started
Note
Please check prior to operation, if the indicated line voltage range on the power supply matches
with your local mains voltage! If you want to use your own power supply, you can ask Thorlabs
for an appropriate power connector cable.
· If necessary, mount the unit on your optical table or application. The unit has three tapped
mounting holes (see chapter Mounting the PDF10x Series for details).
· Make sure, the PDF10x is switched off (see Operating Elements )
· Switch the power supply to your local main voltage (100 VAC, 120VAC, or 230VAC):
· Plug the power connector cable into the POWER IN.
· Plug the power supply into a 50-60Hz, 100 VAC, 120VAC, or 230VAC outlet, turn power
supply on.
· Connect the output with a coaxial cable to your data acquisition device. Please note, that a
high impedance device (>10kOhm) should be used for best performance.
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© 2018 Thorlabs6
PDF10x
3 Operating Instruction
· Turn the power switch to on ("I") while the optical input is protected by the metal cover cap.
· Please check, that OUTPUT offset voltage is within the range listed in Technical Data. A
small drift during warm up period (~5min) is typical.
· Please also check, that noise level is not higher than 5mVRMS. If noise level is significantly
higher, please refer to recommendations and optimize your setup.
· Remove the metal cover cap to detect your optical signal.
· If necessary, mount external optics, filters, apertures or fiber adapters.
· The maximum OUTPUT voltage swing is +10V for high impedance loads (>10kOhm). The
OUTPUT signal should be below this maximum output voltage to avoid amplifier saturation.
· Turn the power switch to O when you are finished the measurements.
Note
To prevent saturation of the amplifier keep the optical input powers less than the saturation
power listed in Technical Data.
Attention
Refer to the Technical Data and pay attention to the optical damage threshold! Exceeding
these values will permanently destroy the detectors!
3.1 General Principle of Operation
The Thorlabs PDF10x series Femtowatt Photoreceivers combines a very low noise Silicon or
InGaAs photodiode with a specially designed ultra low noise transimpedance amplifier with ex-
tremely high gain of up to 1012V/A. This unique combination results in a photoreceiver with
femtowatt sensitivity due to its exceptional low NEP, making them ideal for low-light level detec-
tion applications, such as spectroscopy and fluorescence measurements. Direct detection of
optical power down to ~10 fW is possible; in combination with an optional Lock-In Amplifier
even sub-femtowatt sensitivity can be achieved.
An integrated ultra low noise high gain amplifier provides output signals in the range up to 10V,
the output is short circuit proof.
The new slim line housing includes a removable threaded coupler that is compatible with a
number of Thorlabs 1” and ½” threaded accessories. This allows to conveniently mount ex-
ternal optics, filters, apertures or fiber adapters, as well as providing an easy mounting mechan-
ism using the Thorlabs cage assembly accessories. The PDF10x has three tapped mounting
holes.
The PDF10x is powered by an LDS12B external linear power supply (±12V, 250mA) via a
PICO M8 power connector.
In case of open beam, make sure that the beam is aligned properly to the detector input. If ne-
cessary, use a focusing lens in front of the detector.
If the PDF10x is used in fiber based applications we recommend a Thorlabs fiber connector ad-
apter for coupling between fiber and PDF10x. Please see Ordering Codes and Accessories
for details.
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 FC adapter can be rotated from its ori-
ginal position to check for an improved alignment. For this process apply an input signal with
power below the saturation level while observing the output voltage using a digital voltmeter or
other low-frequency measurement device.
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© 2018 Thorlabs
3 Operating Instruction
7
The maximum output voltage swing is +10V. Saturation of the output will occur at optical input
power greater than CW Saturation Power listed in Technical Data . If necessary, use external
neutral density filters or attenuators to reduce the input light level. Please note, that the
Femtowatt Photoreceivers are extremely sensitive to unwanted stray light. It is essentail to
carefully shield the PDF10x input aperture from any unwanted light sources. Common tech-
niques are baffling or other opaque barriers like black cloths, beam tubes or the use of appro-
priate band pass filters in front of the detector to minimize the influence of stray light.
Warning
The optical damage threshold is 10mW. Exceeding this value will permanently destroy the
Femtowatt Photoreceivers!
3.2 Operating Elements
1 BNC output connector
2 PICO M8 DC input power connector
3 ON-OFF switch
4 Photo detector
5 External SM1 (1.035"-40) thread
6 Internal SM05 (0.535"-40) thread
Note
Due to limitations in the IC, the high speed amplifier used in these devices may become un-
stable, exhibiting oscillations or negative output, if the power supply voltage is applied when the
module is on. So, prior to connect the external power supply, please make sure the power-on
switch on your PDF10x is in OFF position ("O").
11

© 2018 Thorlabs8
PDF10x
3.3 Properties and specifications
Responsivity
The Thorlabs PDF10x delivers an output voltage, which is a function of incident light power
POPT, detector responsivity  ( l ) and transimpedance gain G given by:
The responsivity  ( l ) for a given wavelength can be read from the diagrams (see technical
PDF10A or PDF10C ) to estimate the output voltage. Please note, that transimpedance
gain tolerance is ±10% for an individual unit due to extremely high feedback resistors used for
the transimpedance amplifier. Temperature changes or even humidity changes may affect
transimpedance gain.
Output Voltage
The maximum output voltage swing of output is 10V for high impedance loads (>10kOhm).
Depending on wavelength responsivity  ( l ) of the detector, the amplifier will reach saturation
at optical input power greater than CW Saturation Power listed in Technical Data. The output
signal should be below the maximum output voltage to avoid saturation.
Offset
The amplifier offset voltage is factory set to zero at 23°C ambient temperature. Due to the ex-
tremely high feedback resistors used in the transimpedance amplifiers small temperature
changes or even humidity changes may affect offset voltage. Therefore it is recommended to
use the PDF10x in a constant temperature environment after a short warm up period (~5min)
for exact DC light level measurements.
Frequency Response
Typical frequency response curves of the output for model PDF10A and PDF10C can be found
in the appendix (PDF10A and PDF10C ). For this measurement a test signal was fed
through an optical chopper and fiber-coupled to the PDF10x input. The output voltage amp-
litude was measured with a oscilloscope.
Rise / Fall Time
Rise/Fall time measurement were carried out with the same setup described above. Typical
measurement data for different modulation frequencies can be found as well in the appendix
(see PDF10A resp. PDF10C ).
Noise
Noise is being characterized by different specifications. The spectral noise of PDF10X was
measured using a 200kSample/s A/D converter. The power density spectrum was calculated
from the sampled values with respect to transimpedance gain and detector responsivity. The
optical Input of the PDF10x was blocked. Curves can be found in the appendix (see PDF10A
or PDF10C ).
Other noise specifications are the NEP (Noise Equivalent Power) and the overall RMS output
noise, specified for a defined bandwidth. These parameters are stated in Technical Data ).
3.4 Mounting the PDF10x Series
The PDF10x series is housed in a rugged 53.4 x 43.2 x 21mm3 shielded aluminum enclosure.
The new slim line housing includes a removable threaded coupler that is compatible with a
number of Thorlabs 1” and ½” threaded accessories. This allows convenient mounting of ex-
ternal optics, filters, apertures or fiber adapters, as well as providing an easy mounting mechan-
ism 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 mini-
12 14
12 14
13 15
13
15
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© 2018 Thorlabs
3 Operating Instruction
9
mize the thickness of the PDF10x so it can fit into tight spaces. For maximum flexibility the
PDF10x has three 8-32 (M4 for /M metric version) tapped mounting holes to mount the unit to a
post or pedestal.
Possible mounting options for PDF10x

© 2018 Thorlabs10
PDF10x
4 Maintenance and Service
Protect the PDF10x from adverse weather conditions. The PDF10x 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!
Do not open the power supply unit!
Cleaning
To clean the PDF10x series housing, use a mild detergent and damp cloth. Do not soak the
unit in water or use solvent based cleaners.
When cleaning the window of the photodetector, please remember that is a sensitive optical
device. Gently blow off any debris using compressed air and wipe gently with an optic tissue
wetted with propane.
4.1 Recommendations
Please always remember that the PDF10x are extremely sensitive devices. Careful shielding of
the PDF10x from any unwanted light sources is essential. Common techniques are baffling or
other opaque barriers like black cloths or beam tubes. Even a small power-on indicator LED far
away from the PDF10x in a completely obscured lab can affect power measurements at
femtowatt levels.
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 PDF10x when it is exposed to ambient light. The amplifier
will saturate but unlike Photomultiplier Tubes it will not be damaged or saturated 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 PDF10x. If possible, you can also rotate the PDF10x 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 ex-
tremely high feedback resistors used in the transimpedance amplifiers small temperature
changes or even humidity changes may affect offset voltage. Therefore it is recommended to
use the PDF10x in a constant temperature environment after a short warm up period (~5min)
for exact DC light level measurements.
Due to limitations in the IC, the high speed amplifier used in these devices may become un-
stable, exhibiting oscillations or negative output, if the power supply voltage is applied when the
module is on. So, prior to connect the external power supply, please make sure the power-on
switch on your PDF10x is in OFF position ("0") - see Operating elements .
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© 2018 Thorlabs
5 Appendix
11
5 Appendix
5.1 Technical Data
Specification
PDF10A
PDF10C
Detector Material
Silicon
InGaAs / PIN
Detector Wavelength Range
320 - 1100nm
800 - 1700nm
Max. Responsivity
typ. 0.6A/W @ 960nm
typ. 1.0A/W @ 1550nm
Detector Active Area
1.1 x 1.1mm2
Æ 0.5mm
Transimpedance Gain
1 x 1012 V/A ± 10%
1 x 1011 V/A ± 10%
Max. Conversion Gain
0.6 x 1012 V/W ± 10%
1 x 1011 V/W ± 10%
Output Bandwidth (-3dB)
DC - 20Hz
DC - 25Hz
Rise/Fall Time (10% -90%)
22ms
19ms
CW Saturation Power
16pW
100pW
Max. Input Power
(photodiode damage threshold))
10mW
Minimum NEP (DC to 3dB bandwidth)
1.4fW/ Ö Hz
7.5fW/ Ö Hz
Integrated Noise (DC to 3dB bandwidth)
6.5 fWRMS
35 fWRMS
Overall output voltage noise, typ.
6.5 mVRMS
3.5 mVRMS
Electrical Output, Impedance
BNC, 200Ω
Maximum Output Voltage
10V
DC-Offset Electrical Output
< ± 150mV
Size
53.4 x 43.2 x 21 mm³
Power Supply
± 12V, 250 mA
All technical data are valid at 23 ± 5°C and 45 ± 15% rel. humidity (non condensing)

© 2018 Thorlabs12
PDF10x
5.1.1 PDF10A
PDF10A Detector Responsivity
PDF10A output frequency response

© 2018 Thorlabs
5 Appendix
13
PDF10A output time response
PDF10A spectral noise

© 2018 Thorlabs14
PDF10x
5.1.2 PDF10C
PDF10C detector responsivity
PDF10C output frequency response

© 2018 Thorlabs
5 Appendix
15
PDF10C output time response
PDF10C spectral noise

© 2018 Thorlabs16
PDF10x
5.2 Dimensions

© 2018 Thorlabs
5 Appendix
17
5.3 Certifications and Compliances
Category
Standards or description
EC Declaration of
Conformity - EMC
Meets intent of Directive 2004/108/EC 1 for Electromagnetic Compatibility. Compliance was
demonstrated to the following specifications as listed in the Official Journal of the European
Communities:
EN 61326-1:2006
Electrical equipment for measurement, control and laboratory use –
EMC requirements:
Immunity: complies with basic immunity test requirements 2.
Emission: complies with EN 55011 Class B Limits 2,4,
IEC 610003-2 and IEC 61000-3-3.
IEC 61000-4-2
Electrostatic Discharge Immunity (Performance Criterion B)
IEC 61000-4-3
Radiated RF Electromagnetic Field Immunity (Performance Criterion
A)
IEC 61000-4-4
Electrical Fast Transient / Burst Immunity (Performance Criterion B)
IEC 61000-4-6
Conducted RF Immunity (Performance Criterion A)
FCC EMC Compli-
ance
Emissions comply with the Class B Limits of FCC Code of Federal Regulations 47, Part 15,
Subpart B 2,4.
EC Declaration of
Conformity - Low
Voltage
Compliance was demonstrated to the following specification as listed in the Official Journal
of the European Communities:
Low Voltage Directive 2006/95/EC 7
EN 61010-1:2001
Safety Requirements for Electrical Equipment for Measurement,
Control and Laboratory Use - Part 1: General Requirements
U.S. Nationally Re-
cognized Testing
Laboratory Listing
UL 61010-1 2nd ed.
ISA-82:02.01 2nd ed.
Canadian Certifica-
tion
CAN/CSA C22.2 No.
61010-1 2nd ed.
Additional Compli-
ance
IEC 61010-1:2001
Equipment Type
Test and Measuring
Safety Class
Class I equipment (as defined in IEC 60950-1:2001)
1 Replaces 89/336/EEC.
2 Compliance demonstrated using high-quality shielded interface cables shorter than or equal to 3 meters.
4 Emissions, which exceed the levels required by these standards, may occur when this equipment is connected to a test object.
7 Replaces 73/23/EEC, amended by 93/68/EEC

© 2018 Thorlabs18
PDF10x
5.4 Warranty
Thorlabs warrants material and production of the PDF10x for a period of 24 months starting
with the date of shipment. During this warranty period Thorlabs will see to defaults by repair or
by exchange if these are entitled to warranty.
For warranty repairs or service the unit must be sent back to Thorlabs. The customer will carry
the shipping costs to Thorlabs, in case of warranty repairs Thorlabs will carry the shipping costs
back to the customer.
If no warranty repair is applicable the customer also has to carry the costs for back shipment.
In case of shipment from outside EU duties, taxes etc. which should arise have to be carried by
the customer.
Thorlabs warrants the hard- and/or software determined by Thorlabs for this unit to operate
fault-free provided that they are handled according to our requirements. However, Thorlabs
does not warrant a fault free and uninterrupted operation of the unit, of the software or firmware
for special applications nor this instruction manual to be error free. Thorlabs is not liable for
consequential damages.
Restriction of Warranty
The warranty mentioned before does not cover errors and defects being the result of improper
treatment, software or interface not supplied by us, modification, misuse or operation outside
the defined ambient stated by us or unauthorized maintenance.
Further claims will not be consented to and will not be acknowledged. Thorlabs does explicitly
not warrant the usability or the economical use for certain cases of application.
Thorlabs reserves the right to change this instruction manual or the technical data of the de-
scribed unit at any time.
5.5 Exclusion of Reliability and Copyright
Thorlabs has taken every possible care in preparing this document. We however assume no li-
ability for the content, completeness or quality of the information contained therein. The content
of this document is regularly updated and adapted to reflect the current status of the hardware
and/or software. We furthermore do not guarantee that this product will function without errors,
even if the stated specifications are adhered to.
Under no circumstances can we guarantee that a particular objective can be achieved with the
purchase of this product.
Insofar as permitted under statutory regulations, we assume no liability for direct damage, indir-
ect damage or damages suffered by third parties resulting from the purchase of this product. In
no event shall any liability exceed the purchase price of the product.
Please note that the content of this document is neither part of any previous or existing agree-
ment, promise, representation or legal relationship, nor an alteration or amendment thereof. All
obligations of Thorlabs result from the respective contract of sale, which also includes the com-
plete and exclusively applicable warranty regulations. These contractual warranty regulations
are neither extended nor limited by the information contained in this document. Should you re-
quire further information on this product, or encounter specific problems that are not discussed
in sufficient detail in the document, please contact your local Thorlabs dealer or system in-
staller.
All rights reserved. This document may not be reproduced, transmitted or translated to another
language, either as a whole or in parts, without the prior written permission of Thorlabs.
Copyright © Thorlabs 2018. All rights reserved.