THORLABS PDA8000-1 User manual

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Operation Manual
Thorlabs Instrumentation
PRO8000 (-4) / PRO800
Photo current module PDA8000
2012

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© 2012 Thorlabs
Version: 3.2
Date: 27.03.2012
Copyright©2012, Thorlabs

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© 2012 Thorlabs
Contents Page
1General description of the PDA8000 2
1.1 Safety 2
1.2 Features 4
1.3 Technical data 5
1.4 Operating elements at the front of the module 6
1.5 Presettings 7
1.5.1 Offset adjustment 7
1.6 Connecting the photodiode 7
2Operating the PDA8000 8
2.1 Functions in the main menu 8
2.1.1 Display 8
2.1.2 Selecting a module 8
2.2 Functions in the channel menu 9
2.2.1 Display 9
2.2.2 Changing parameters 10
2.2.3 Selecting the polarity of the photo diode 11
2.2.4 Calibrating the photo diode 11
2.2.5 Setting the bias voltage 11
2.2.6 Switching on the bias voltage of the photo diode 12
2.2.7 Setting the measurement range 12
2.2.8 Measuring the forward voltage (option PDA8000-FWD) 13
2.3 Display error messages 13
3Communication with a control computer 14
3.1 General information 14
3.1.1 Nomenclature 14
3.1.2 Data format 14
3.2 Commands 15
3.2.1 Selecting the module slot 15
3.2.2 Selecting a port (PORT) 15
3.2.3 Calibrating a photo diode (CALPD) 15
3.2.4 Programming the forward current (IFWD) 16
3.2.5 Reading the photo diode current (IPD) 16
3.2.6 Switch the bias voltage on and off (PDBIA) 17
3.2.7 Select the photo diode polarity (PDPOL) 17
3.2.8 Reading the optical power (POPT) 18
3.2.9 Selecting the measurement range (RANGE) 18
3.2.10 Querying the module type 19

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3.2.11 Programming the bias voltage (VBIAS) 19
3.2.12 Reading the forward voltage (VFWD) 20
3.3 IEEE error messages of an PDA8000 21
3.4 Status reporting 22
3.4.1 Standard event status register (ESR) 23
3.4.2 Standard event status enable register (ESE) 23
3.4.3 Status byte register (STB) 23
3.4.4 Service request enable register (SRE) 24
3.4.5 Reading the STB by detecting SRQ 24
3.4.6 Reading the STB by "*STB?" command 24
3.4.7 Reading the STB by serial poll 24
4Service and Maintenance 25
4.1 General remarks 25
4.2 Troubleshooting 25
5Appendix 28
5.1 Warranty 28
5.2 Thorlabs “End of Life” policy (WEEE) 29
5.2.1 Waste treatment on your own responsibility 29
5.2.2 Ecological background 30
List of abbreviations 31
5.3 List of figures 32
5.4 Certifications and compliances 33
5.5 Copyright 34
5.6 Addresses 35

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We aim to develop and produce the best solution for your application in the
field of optical measurement technique. To help us to come up to your
expectations and develop our products permanently 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.
In the displays shown by the PRO8 you may find the name PROFILE.
PROFILE was the name of the manufacturer before it was acquired by Thorlabs
and renamed to Thorlabs.
Thorlabs
This part of the instruction manual contains every specific information on how to
operate the photo current module PDA8000. A general description is followed by
explanations of how to operate the unit manually. You will also find every information
about remote control via the IEEE 488 computer interface.
Attention
This manual contains “WARNINGS” and “ATTENTION” label in this
form, to indicate dangers for persons or possible damage of equip-
ment.
Please read these advises carefully!
NOTE
This manual also contains “NOTES” and “HINTS” written in this form.

2 Safety
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1 General description of the PDA8000
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.
Before applying power to your PRO8000 (-4) / PRO800 system, make
sure that the protective conductor of the 3 conductor mains power
cord is correctly connected to the protective earth contact of the
socket outlet!
Improper grounding can cause electric shock with damages to your
health or even death!
Modules may only be installed or removed with the mainframe
switched off.
All modules must be fixed with all screws provided for this purpose.
Modules of the 8000 series must only be operated in the mainframe
PRO8000, PRO8000-4 or PRO800.
All modules must only be operated with duly 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 dispatchable if duly packed into the
complete original packaging including the plastic form parts. If
necessary, ask for a replacement package.

Safety 3
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 Attention 
Semiconductor laser modules can deliver up to several 100mW of
(maybe) invisible laser radiation!
When operated incorrectly, this can cause severe damage to your
eyes and health!
Be sure to pay strict attention to the safety recommendations of the
appropriate laser safety class!
This laser safety class is marked on your PRO8000 (-4) / PRO800
plug-in module or on your external laser source used.
 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 EN 50 082-1.

4 Features
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1.2 Features
Utmost precision
The single or dual channel photocurrent amplifier modules PDA8000 offer a
maximum of precision and sensitivity. The polarity of the photodiode is neverthe-
less free selectable.
Different operating modes
The photodiode may either be operated photovoltaic or photoconductive by setting
a bias voltage of 0 ... 10V.
7 measurement ranges
For a low noise measurement with 15 bit resolution plus sign there are seven
measurement ranges from 10 nA to 10 mA. The lowest, still detectable current is
about 0,1 pA (!)
Optical power measurement
Since the photocurrent amplifier modules can be calibrated by selecting the
photodiode sensitivity they can be used for precise optical power measurements
after calibration.
Forward voltage measurement (optional)
Optionally it will be possible to measure the forward voltage of the photodiode with
a selectable measurement current between 0.01 and 10 mA. (option PDA8000-
FWD).
Extensive filtering
The mains filter installed in the mainframe and the careful shielding of the
transformer, the microprocessor and the module itself will provide an excellent
suppression of noise and ripple.
Selecting the reference ground
Additionally the reference ground for the measurements can be adapted to the
measurement setup.
LabVIEW®- and LabWindows/CVI®-driver
For the PDA8000 Thorlabs supplies LabVIEW®- and LabWindows/CVI®-drivers for
MS Windows 32.
Please refer to our homepage for latest driver updates.
http://www.thorlabs.com

Technical data 5
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1.3 Technical data
(All technical data are valid at 23 ± 5°C and 35 ±15% humidity)
Photocurrent amplifier module PDA8000-1(2)
General data
Photodiode current range 10 nA ... 10 mA1)
Resolution 16 bit
Polarity of photodiode selectable
Setting range of bias voltage (can be switched off) 0.1 V ... 10 V
Setting range of the photodiode coefficient 0.001 ... 5.000 A / W
Temperature coefficient 50 ppm/K
Input impedance 0(virtual ground)
Operating temperature 0 … + 40°C
Storage temperature - 40 … + 70°C
Forward voltage measurement for channel 1 (opt. PDA8000-FWD)
Measurement technique 2-wire technique
Measurement current 0.01 ... 10 mA (5%)
Measurement range UFWD 0 ... 2 V2)
Resolution 0.3 mV
Accuracy ± 5 mV
Connectors
Photodiode BNC
Measurement ranges
Current range Resolution Accuracy
10 mA 0.1 A 0.025 % f.s.
1 mA 10 nA 0.025 % f.s.
100 A 1 nA 0.025 % f.s.
10 A 0.1 nA 0.025 % f.s.
1 A 10 pA 0.025 % f.s.
100 nA 1 pA 0.250 % f.s.3)
10 nA 0.1 pA 0.800 % f.s.3)
1other ranges on request
2reduces to 0 ... 1 V for IFWD > 8 mA
3higher accuracy can be reached by repeated measurements

6 Operating elements at the front of the module
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1.4 Operating elements at the front of the module
LED SELect
LED error
Connector jack input 1
Offset adjust input 1
Connector jack input 2
Offset adjust input 2
Figure 1 Operating elements on the PDA8000-2 front panel

Presettings 7
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1.5 Presettings
1.5.1 Offset adjustment
Connect the photodiode and all other components of the complete system (the
photodiode must be in total darkness).
Switch on the PRO8000 (-4) / PRO800.
Select 10 A-range.
(Refer to chapter 2.2.7, "Setting the measurement range" on page 12)
Enter the channel menu to observe the photodiode current.
Adjust the offset with the offset potentiometer of the corresponding channel to
"zero".
(Refer to chapter 1.4, "Operating elements at the front of the module" on page 6)
NOTE:
When using photodiodes with a dark current higher than 1 nA only the
ground conductor of the photodiode is to be connected.
1.6 Connecting the photodiode
Photodiodes can be connected to the BNC jacks of an input with both polarities. The
outer conductor of the BNC jack is always grounded.
Both polarity settings of the PDA8000 (AG = "anode ground" and CG = "cathode
ground") can be used depending on how the photodiode is connected to the BNC
jack.
If one of the connectors of the photodiode itself is connected to ground (e.g. as with
many housed laser diodes) this ground connector has to be connected to the outer
conductor of the BNC jack.
Only one of the polarity settings of the PDA8000 (AG or CG) will then be correct.
If in doubt, the correctly selected polarity yields a positive photo current on the
display.

8 Functions in the main menu
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2 Operating the PDA8000
2.1 Functions in the main menu
2.1.1 Display
The main menu shows the channel number and the photo diode current measured at
input 1
Channel no. Cursor Photo-current
CH1 I1= - 0.1234 nA
CH2
CH3
TUNE
2.1.2 Selecting a module
Select a module for further input by setting the cursor to the channel number of the
desired module.
Use the soft key and .
CH4
Pressing will lead to the channel menu

Functions in the channel menu 9
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2.2 Functions in the channel menu
By pressing the key you enter the channel menu.
Pressing again or will lead back to the main menu.
2.2.1 Display
In the channel menu all parameters of the selected module are shown:
channel no. cursor operating parameters
CH4 I1=+ 0.1234nA
1 CG BIA P1= 0.12345nW
2 CG U BIA1= 0.00 V
CHANGE
monitor diode polarity of input 1 indicator for applied bias voltage
monitor diode polarity of input 2
Only three parameters can be shown at a time, so there is a scroll function. All
parameters are sorted in a virtual list, which can be run through with the cursor:
I1=+ 0.1234nA ...
P1= 0.1234nW UBIA2= 0.00 V
UBIA1= 0.00 V C2=1.12345A/W
C1=1.12345A/W BIA2 = OFF
BIA1 = OFF RNG2 =10.00nA
RNG1 =10.00nA POL2 = CG
POL1 = CG If you use the PDA8000-FWD:
Ifwd=1.1234mA Ifwd= 3.000mA
Ufwd=1.234 V Ufwd= 1.551 V
MEASURE Ifwd MEASURE Ifwd
I2=+ 0.1234nA
P2= 0.1234nW
...

10 Functions in the channel menu
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2.2.2 Changing parameters
To set or change a numerical parameter in the channel menu the respective line is
selected with the cursor:
Example: UBIA1 is to be changed:
CH4 I1=+ 0.1234nA
1 CG P1= 0.12345nW
2 CG UBIA1= 0.00 V
CHANGE
Pressing the key (CHANGE), activates the tuning knob enabling the selected
parameter to be changed. If the selected parameter is a switch parameter (i.e. the
polarity of the photo diode) the function of the soft key will change:
TOGGLE:Polarity PD1
Pressing the right soft key will toggle the polarity.
Pressing terminates the input.
NOTE
Some parameters can not be changed, as they are measurement values
(i.e. the photo diode current) or may not be changed during bias voltage
switched on. In these cases access is denied indicated by a long beep.

Functions in the channel menu 11
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2.2.3 Selecting the polarity of the photo diode
To change the polarity of the photo diode select
POL1 = for input 1
POL2 = for input 2
in the channel menu of the module. It then can be changed to the desired polarity.
(Refer to chapter 2.2.2, "Changing parameters" on page 10)
NOTE
If the selected polarity of the photodiode is wrong the measured photodi-
ode current will be displayed negative. Trying to set a bias voltage or to
measure the forward voltage (opt. PDA8000-FWD) will yield an error
message.
2.2.4 Calibrating the photo diode
If the displayed optical power shall be calibrated, the correct sensitivity of the photo
diode must be entered.
If for example is 0.5 A/W this can be done in the channel menu entering the value
C1=0.5000A/W for input 1
C2=0.5000A/W for input 2
The default value of is 0.1000 A/W. It is valid without specific confirmation.
2.2.5 Setting the bias voltage
Each input can operate with a bias voltage in the range of 0 ... 10 V.
If for example the photo diode shall work with 3.000 V bias voltage this can be
entered in the channel menu :
UBIA1= 3.00 V for input 1
UBIA2= 3.00 V for input 2
(Refer to chapter 2.2.2, "Changing parameters" on page 10)

12 Functions in the channel menu
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2.2.6 Switching on the bias voltage of the photo diode
 Attention 
Before switching the bias voltage on make sure that the photodiode
is poled correctly (inverse direction).
If the photodiode is forward biased with a voltage, a current will flow
through it that could damage or even destroy it.
The bias voltage is switched on by setting the parameter:
BIA1 = ON for input 1
BIA2 = ON for input 2
in the channel menu of the module.
2.2.7 Setting the measurement range
Each input offers 7 measurement ranges.
Measurement range Resolution Accuracy
10 mA 0.1 A 0.025 % f.s.
1 mA 10 nA 0.025 % f.s.
100 A 1 nA 0.025 % f.s.
10 A 0.1 nA 0.025 % f.s.
1 A 10 pA 0.025 % f.s.
100 nA 1 pA 0.250 % f.s.
10 nA 0.1 pA 0.800 % f.s.
To set for example the measurement range to 1 mA full scale, enter
RNG1 =1.000mA for input 1
RNG2 =1.000mA for input 2
In the channel menu.

Display error messages 13
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2.2.8 Measuring the forward voltage (option PDA8000-FWD)
If the PDA8000 is used with the -FWD option the forward voltage (UFWD) of the
photodiode can be measured at input 1. The measurement current (IFWD) used for
measurement can be selected in the range of 0.01 mA to 10 mA and is set by the
parameter:
Ifwd= 5.000mA
To measure the forward voltage (UFWD) select:
MEASURE Ufwd!
Then press the soft key CHANGE twice to do a measurement. The measured voltage
is displayed in the line Ufwd=
2.3 Display error messages
Possible reasons for error messages when try to change parameters:
NOT IF BIAS Attempt to change the polarity of the photo diode, the
measurement range or to start a forward voltage meas-
urement, while a bias voltage is applied.
POLARITY ! Attempt to apply a the bias voltage with wrong polarity
of the polarity of the photodiode.
Possible reasons for error messages during forward voltage measurement
ACCURACY ! Insufficient measurement accuracy (non-linearities or
noise)
OVERFLOW ! The requested forward current could not be reached,
even with the max. possible voltage. Possibly, no photo
diode connected or bad connection.
.

14 General information
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3 Communication with a control computer
3.1 General information
The description of the mainframe of the PRO8000 (-4) / PRO800 includes all
instructions of how to prepare and execute the programming of the system via
IEEE 488 or RS232C computer interface.
Special operation features of a PDA8000 photo current module are described here.
(Refer to chapter 2, "Operating the PDA8000" starting on page 8)
NOTE
All analog values are read and written in SI units, i.e. A (not mA), W (not
mW) etc. Letters may be written in small or capital letters.
3.1.1 Nomenclature
Program messages (PC PRO8000 (-4)) are written in inverted commas:
"*IDN?"
Response messages (PRO8000 (-4) PC) are written in brackets:
:SLOT 1
There is a decimal point: 1.234
Parameters are separated with comma: "PLOT 2,0"
Commands are separated with semicolon: "*IDN?;*STB?"
3.1.2 Data format
According to the IEEE 488.2 specifications all data variables are divided into 4
different data formats:
Character response data (<CRD>)
Is a single character or a string. Examples:
Aor ABGRS or A125TG or A1.23456A
(Refer to IEEE488.2 (8.7.1))
Numeric response data Type 1 (<NR1>)
Is a numerical value with sign in integer notation. Examples:
1 or +1 or -22 or 14356789432
(Refer to IEEE488.2 (8.7.2))
Numeric response data Type 2 (<NR2>)
Is a numerical value with or without sign in floating point notation without exponent.
Examples:
1.1 or +1.1 or -22.1 or 14356.789432
(Refer to IEE488.2 (8.7.3))

Commands 15
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Numeric response data Type 3 (<NR3>)
Is a numerical value with or without sign in floating point notation with exponent with
sign . Examples:
1.1E+1 or +1.1E-1 or -22.1E+1 or 143.56789432E+306
(Refer to IEE488.2 (8.7.4))
3.2 Commands
3.2.1 Selecting the module slot
":SLOT <NR1>" Selects a slot for further programming
<Nr1>=1…8 (PRO8000), 1…2 (PRO800)
":SLOT?" Queries the selected slot
[:SLOT <NR1><LF>]
3.2.2 Selecting a port (PORT)
Programming:
":PORT 1" Selects port 1 for further commands
":PORT 2" Selects port 2 for further commands
Reading:
":PORT?" Reads the selected port
[:PORT <NR1><LF>]
3.2.3 Calibrating a photo diode (CALPD)
Programming:
":CALPD:SET <NR3>" Programs the sensitivity () of the monitor diode in
A/W
Reading:
":CALPD:SET?" Reads the sensitivity () of the monitor diode in
A/W
[:CALPD:SET <NR3><LF>]
":CALPD:MIN?" Reads the allowed minimum sensitivity () of the
monitor diode in A/W
[:CALPD:MIN <NR3><LF>]
":CALPD:MAX?" Reads the allowed maximum sensitivity () of the
monitor diode in A/W
[:CALPD:MAX <NR3><LF>]

16 Commands
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3.2.4 Programming the forward current (IFWD)
NOTE
This command always affects port 1, so you do not need to select the port
1 first. This command is only available for a PDA8000 with the option
PDA8000-FWD
Programming:
":IFWD:SET <NR3>" Programs the forward current of port 1
Reading:
":IFWD:SET?" Reads the forward current of port 1
[:IFWD:SET <NR3><LF>]
":IFWD:MIN?" Reads the allowed minimum forward current of
port 1
[:IFWD:MAX <NR3><LF>]
":IFWD:MAX?" Reads the allowed maximum forward current of
port 1
[:IFWD:MIN <NR3><LF>]
3.2.5 Reading the photo diode current (IPD)
NOTE
Please first select the desired port with the command ":PORT"
Programming:
":IPD:MEAS <NR1>" Programs the photo current to be a measurement
value for “ELCH” on output string position <NR1>
(1...8)
Reading:
":IPD:ACT?" Reads the actual photo diode current
[:IPD:ACT <NR3><LF>]
":IPD:MIN_R?" Reads IPD – ADC = 0000
[:IPD:MIN_R <NR3>]
":IPD:MAX_R?" Reads IPD – ADC = FFFF
[:IPD:MAX_R <NR3>]