THORLABS PM100A User manual

Operation Manual
Thorlabs Instrumentation
Optical Power Meter
PM100A
2011

Version: 17655-D02 REV C
Date: 21.04.2011
Copyright©2011, Thorlabs, Germany

Contents page
1General Information 4
1.1 Safety 5
1.2 Ordering Codes and Accessories 7
2Getting Started 8
3Unpacking 8
3.1 Preparation 8
3.2 Physical Overview 9
3.2.1 Front Panel 9
3.2.2 Side Panel 9
3.2.3 Rear Panel 10
3.2.4 Bottom 10
3.2.5 Display 11
4Operating the PM100A 12
4.1 Connecting a Power Sensor 12
4.2 Controlling the PM100A 12
4.2.1 Navigating the Menus 12
4.2.2 System Settings 12
4.2.3 Power Measurement 14
4.2.3.1 Range and Scale Control 14
4.2.3.2 Wavelength Correction 14
4.2.3.3 Zeroing 15
4.2.3.4 Setting an Attenuation / Gain Factor 16
4.2.3.5 Relative Power Measurement 17
4.2.4 Display Options 17
4.2.5 Sensor Dependent Functions 18
4.2.5.1 Photodiode Sensors 18
4.2.5.2 Thermal Power Sensors 19
4.3 Analog Output 21
4.4 Tune Sound 21
4.5 Battery Charging 22
5Measurement Considerations 23
5.1 Choosing the right Sensor 23
5.2 Reducing Noise for High Accuracy Measurements 23
5.3 Power Measurement of Pulsed Signals 24
5.4 Line width of Light Sources 24
5.5 Temperature Effects on Thermal Sensors 24
5.6 Ambient and Stray Light 25
5.7 Back Reflection 25

2
5.8 Beam Diameter vs. Active Sensor Area 25
5.9 Fiber Based Measurements 26
6Computer Interface 27
6.1 PM100 Utility Software 27
6.1.1 Front Panel 28
6.1.2 Description of the Front Panel Elements: 28
6.2 Firmware Update 31
6.3 Simple LabVIEW Example using SCPI Commands 32
6.4 Using the Instrument Drivers 36
6.5 SCPI Commands 37
6.5.1 An Introduction to the SCPI language 37
6.5.2 IEEE488.2 Common Commands 40
6.5.2.1 Command summary 40
6.5.2.2 Command reference 41
6.5.2.3 PM100D specific SCPI Command Reference 42
6.6 Maintenance and Repair 52
6.7 Maintenance 52
6.8 Troubleshooting 53
7Appendix 54
7.1 Warranty 54
7.2 Certifications and compliances 55
7.3 Technical data 56
7.4 Pin Assignment of the Sensor Connector 58
7.5 Thorlabs „End of Life‟ policy (WEEE) 59
7.5.1 Waste treatment on your own responsibility 59
7.5.2 Ecological background 60
7.6 List of figures 61
7.7 Addresses 62

1.1 Safety
3
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 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.
Thorlabs
This part of the instruction manual contains every specific information on the
PM100A handheld optical power meter. A general description is followed by
explanations of how to operate the unit manually. You will also find information about
a simple remote control of the unit.
Attention
This manual contains „WARNINGS” and „ATTENTION” labels in this
form, to indicate danger for persons or possible damage to equip-
ment.
Please read these advises carefully!
NOTE
This manual also contains „NOTES” and „HINTS” written in this form.

1.1 Safety
4
1 General Information
The PM100A Handheld Optical Power Meter is designed to measure the optical
power of laser light or other monochromatic or near monochromatic light sources and
the energy of pulsed light sources.
The space-saving, battery powered design and compatibility to all Thorlabs “C-Type”
Photodiode and Thermal sensors, and custom Photodiode and Thermal detectors,
featured with a fast USB device interface open a wide range of applications in
Manufacturing, Quality Control, Quality Assurance, and R&D for stationary and field
use.
The unit combines a precise 4 digit power readout with a mechanical, mirror
supported analog needle meter to perform laser tuning tasks or watching trends.
Please refer to the user manual on the data carrier supplied with the unit for detailed
function description.
The provided software, including drivers and applications for LabVIEW and C makes
it easy to integrate the instrument in test and measurement systems.
A rechargeable lithium polymer battery allows long intervals between the charging
cycles. The unit can be recharged with the supplied AC adapter or via USB
connection to a PC or laptop.

1.1 Safety
5
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.
The power meter PM100A must not be operated in explosion endan-
gered environments!
Sensor, photodiode and control inputs and outputs must only be
connected with duly shielded connection cables.
Only with written consent from Thorlabs may changes to single compo-
nents be carried out or components not supplied by Thorlabs be used.
Do not remove covers!
Refer servicing to qualified personal!
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).

1.1 Safety
6
Attention 
The following statement applies to the products covered in this
manual, unless otherwise specified herein. The statement for other
products will appear in the accompanying documentation.
Note: This equipment has been tested and found to comply with the
limits for a Class B digital device, pursuant to Part 15 of the FCC
Rules and meets all requirements of the Canadian Interference-
Causing Equipment Standard ICES-003 for digital apparatus. These
limits are designed to provide reasonable protection against harmful
interference in a residential installation. This equipment generates,
uses, and can radiate radio frequency energy and, if not installed and
used in accordance with the instructions, may cause harmful inter-
ference to radio communications. However, there is no guarantee
that interference will not occur in a particular installation. If this
equipment does cause harmful interference to radio or television
reception, which can be determined by turning the equipment off and
on, the user is encouraged to try to correct the interference by one or
more of the following measures:
▪ Reorient or relocate the receiving antenna.
▪ Increase the separation between the equipment and receiver.
▪ Connect the equipment into an outlet on a circuit different from
that to which the receiver is connected.
▪ Consult the dealer or an experienced radio/T.V. technician for help.
Thorlabs GmbH is not responsible for any radio television interfer-
ence caused by modifications of this equipment or the substitution
or attachment of connecting cables and equipment other than those
specified by Thorlabs GmbH. The correction of interference caused
by such unauthorized modification, substitution or attachment will
be the responsibility of the user.
The use of shielded I/O cables is required when connecting this
equipment to any and all optional peripheral or host devices. Failure
to do so may violate FCC and ICES rules.

1.2 Ordering Codes and Accessories
7
1.2 Ordering Codes and Accessories
Order Code
Description
PM100A
Handheld Power Meter Console
Photodiode Power Sensors:
Order Code
Type
Detector
Aperture
mm
Wavelength
nm
Power
W
S120C
Compact Sensor
Si
9.5
400 - 1100
50n - 50m
S120VC
Compact Sensor
UV-Si
9.5
200 - 1100
50n - 50m
S121C
Compact Sensor
Si
9.5
400 - 1100
500n - 500m
S122C
Compact Sensor
Ge
9.5
700 - 1800
50n - 40m
S130C
Slim Sensor
Dual Range
Si
9.5
400 - 1100
5n - 5m
500n - 500m
S130VC
Slim Sensor
Dual Range
UV-Si
9.5
200 - 1100
5n - 5m
50n - 50m
S132C
Slim Sensor
Dual Range
Ge
9.5
700 - 1800
1200 - 1800
5n - 5m
500n - 500m
S140C
Integr. Sphere (1”)
Si
5.0
350 - 1100
1µ - 500m
S144C
Integr. Sphere (1”)
InGaAs
5.0
800 - 1700
1µ - 500m
S142C
Integr. Sphere (2”)
Si
12
350 - 1100
10µ - 20
S145C
Integr. Sphere (2”)
InGaAs
12
800 - 1700
1µ - 3
S145C
Integr. Sphere (2”)
InGaAs
12
800 - 1700
10µ - 20
S150C
Fiber Head
Si
3.6 x 3.6
350 - 1100
100p - 5m
S151C
Fiber Head
Si
3.6 x 3.6
400 - 1100
1n - 20m
S154C
Fiber Head
InGaAs
2.0
700 - 1700
100p - 5m
S155C
Fiber Head
InGaAs
2.0
700 - 1700
1n –20m
Thermal Power Sensors:
Order Code
Type
Aperture
mm
Wavelength
nm
Power
W
S302C
Thermally Stabilized
Thermal Absorber
12
190 - 25000
100µ - 2
S310C
Thermal Surface Absorber
20
190 - 25000
10m - 10
S314C
Thermal Surface Absorber
25
190 - 10600
10m - 60
S322C
Thermal Surface Absorber
25
190 - 10600
100m - 250
S350C
Thermal Surface Absorber
Excimer Coating
40
190 - 1100
and 10600
10m - 60
S370C
Thermal Volume Absorber
for high peak power lasers
25
400 - 5200
10m - 15
Please visit our homepage http://www.thorlabs.com for various accessories like fiber
adapters, posts and post-holders, data sheets and further information.

3.1 Preparation
8
2 Getting Started
3 Unpacking
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 PM100A mechanically and electrically.
Verify that you have received the following items within the hard-case:
1. PM100A power meter console
2. Plug-In power supply with Interchangeable primary plug for USA, UK, Europe,
and Australia
3. USB cable, type „A‟ to „mini-B‟
4. Quick-start guide
5. USB memory stick with instrument drivers, user application and operation
manual
6. Certificate of Calibration
3.1 Preparation
Configure the plug-in power supply with the primary plug for your local power supply.
Connect a suitable power or energy sensor.
Turn the unit on by pressing the power button in the side panel.
After switching on the unit, the graphics display will show the device status and then
jump to the last measurement screen before power down.
The PM100A is immediately ready to use after turning on.

3.2 Physical Overview
9
3.2 Physical Overview
3.2.1 Front Panel
Analog Meter Needle Zero Adjust Graphics Display
(Switch off unit prior to adjusting!)
Figure 1 Physical Overview Front Panel
3.2.2 Side Panel
Figure 2 Physical Overview Side Panel
Function Keys:
Navigation: 
Enter/Edit: OK
Wavelength: λ
Relative Measure: Δ
Backlight Key: 
On/Off Switch USB Connector Sensor Connector (DB9 female)
DC Input (Charger) Analog Output (SMA)

3.2 Physical Overview
10
3.2.3 Rear Panel
Figure 3 Rear View
3.2.4 Bottom
Figure 4 Physical Overview Bottom View
Mounting Thread 1/4“-20
Pull here to lift the support
Removable Protective
Rubber Boot

3.2 Physical Overview
11
3.2.5 Display
Figure 5 Display Setup
Operation Overview Standard Display:
Function
Menu Key
Item
OK



R_.__ _W
Auto set Meas. Range
Range Down
Range Up
S _.__ _W
Auto set Needle Scale
Zoom In Scale
Zoom Out Scale
Browse
ZERO
Perform Zeroing
(No Function)
Menu
TUNE 
Toggle Tune Sound
Reset Maximum Power Value
Items
MENU
Enter/Exit System Menu
Switch to Statistics View
Operation Overview Statistics View:
Function
Menu Key
Item
OK



R _.__ _W
Auto set Meas. Range
Range Down
Range Up
S _.__ _W
Auto set Needle Scale
Zoom In Scale
Zoom Out Scale
Browse
HOLD / RUN
Hold / Run Statistics
Reset Statistics Values
Menu
TUNE 
Toggle Tune Sound
Reset Statistics Values
Items
MENU
Enter/Exit System Menu
Switch to Standard View
Operating Wavelength
Menu Items (Soft Buttons)
4 digit Power
Readout with units
Power Range
Setting
Power Scale Setting
Delta Power Scale
Power Scales
Information, Status and
Warning Indicators

4.1 Connecting a Power Sensor
12
4 Operating the PM100A
4.1 Connecting a Power Sensor
The PM100A supports all Thorlabs „C-Series photodiode and thermal sensors.
These can easily identified against older versions of Thorlabs power sensors by their
red connector housing. The console will not recognize sensors from the „A‟ and „B‟
series. Please contact Thorlabs for the upgrade of old sensors with „C-Series‟
connectors.
To plug or remove a sensor slightly press on the two bolts in the connector housing,
that fix it by resilience. Sensors can be „hot-swapped‟ to the console, after
recognizing a new valid sensor the type and calibration data will be downloaded to
the console in approximately 2 seconds, and the unit is ready to operate with the
new sensor.
The PM100A also supports custom detectors, please refer to chapter 4.2.2 for the
console measurement settings and chapter 7.4 for the connector pin-out.
4.2 Controlling the PM100A
4.2.1 Navigating the Menus
The measurement screens contain of five menu items (soft buttons) that are
arranged in a column in the right of the graphics display. These can be navigated
with the up and down () keys and controlled by the left and right () keys
and/or the enter/edit (OK) key
The focus is always on the button in inverse presentation .
4.2.2 System Settings
After navigating to the bottom soft button MENU and confirming it with the OK key
the system menu can be scrolled with the or keys. To perform the initial
adjustments the settings can be edit or changed with the or keys on ring
controls or by using all navigation keys for numeric controls.
The menu is arranged on three pages with four lines each. The items depend on the
connected sensor. To leave the system menu press the OK key or navigate down or
up to the „EXIT‟ item and confirm with OK.

4.2 Controlling the PM100A
13
Page 1: Measurement Settings
Bandwidth Sets input bandwidth to High or Low ()
(only visible with connected photodiode sensor)
Accelerator Enables/disables the speed up circuit ()
(only visible with connected thermal sensors)
Attenuation Includes a filter or beam splitter for the power calculation.
The input is in dB. When an attenuation is set, the value is
displayed in the status indicator. ()
Line Filter Sets the unit to the local line frequency 50Hz/60Hz
to avoid aliasing effects ()
Adapter Type Sets the PM100A into the mode to measure photo current
or thermal voltage. Please refer to the chapters 4.2.5.1.2,
4.2.5.2.2 and 7.4 for connecting custom sensors. ()
Page 2: Console Settings
Interface Shows the remote status. Press or to set the unit
back to local mode.
Backlight Sets the brightness of the LCD and key backlight.
The setting range is 0 (off) –100% (maximum). ()
Battery Timer The unit automatically powers off in battery operation after
a certain time without user action. This feature can be set
to 10 or 60 minutes, or switched off; and is not active
when an external power supply (AC adapter or USB) is
connected. ()
Firmware Upload Needs to be set to „ON‟ before uploading a new firmware
version. The function will automatically reset to „OFF‟ after
powering down. ()
Page 3: System Information
Console InformationShows device type, serial number and calibration date.
()
Sensor InformationShows type and serial number of the connected
power sensor. ()
Tau Sets the time constant for custom thermal sensors. (only
visible with connected custom thermal sensor) ()
EXIT Aborts the system menu and switches back to the last
measurement screen. (OK)

4.2 Controlling the PM100A
14
4.2.3 Power Measurement
4.2.3.1 Range and Scale Control
4.2.3.1.1 Measurement Range Control
Navigate to the topmost menu item R -.-- -W ; 6 power corresponding current or 4
power corresponding voltage ranges can be adjusted manually with the or 
keys. Pressing the OK key the unit performs a nonrecurring auto-ranging until the
optimum range has been found for the currently measured power level. The range
control menu item indicates the particular full range value in Watts.
A permanent auto-range mode is only available in remote operation.
4.2.3.1.2 Needle Scale Control
After setting the measurement range the unit automatically selects the needle scale,
where the full power range is covered. To change the needle scale navigate to the
S -.-- -W menu item. With the or keys the scale can be optimized to different
end scales for best readability of the power value (zoom function). This adjustment
can also be automated by pressing the OK key. The scale control menu item
indicates the particular full scale value in Watts.
The scales end have a fixed 1 –2 –5 grid, therefore it is possible that the full scale
range may be higher than the power range. In such a case, when the power level is
exceeding the power range, the needle will deflect to the right stop and the readout
value will indicate „HIGH‟.
4.2.3.2 Wavelength Correction
Most power and energy sensors show a dependent behaviour in their spectral
response. For accurate measurements it is important to set the PM100A to the
wavelength of the light to measure.
Pressing the λkey leads to a wavelength menu with 8+1 individually configurable
sensor independent settings. The currently set operating wavelenght is indicated by
a following arrow () and has focus when entering the menu. Select the desired
operating wavelength by navigating with the  keys and confirming with OK.
The λkey allows to exit without changing the operating wavelength.
λ

4.2 Controlling the PM100A
15
To preconfigure or edit a wavelength item, navigate to it and keep the OK key
pressed until the last digit gets underlined. Set the desired wavelength with the
 keys and confirm with OK.
When selecting a wavelength that is not applicable for the connected sensor a
warning sound will appear and the unit will keep the previous wavelength setting.
Wavelength setting in remote operation will overwrite the down to the right value.
Figure 6 Wavelength Correction
4.2.3.3 Zeroing
Confirming the ZERO menu item with OK, the unit performs an automated zero
adjustment and from now on takes into account this zero level for the power readout
calculation. This feature is used to zeroing thermal sensors, performing dark current
adjustment on photodiode sensors or suppressing small ambient light levels. When
the initial power level is too high, a failure message will appear that is prompting to
cover the power sensor prior to zero adjustment.
Indicator that sensor
needs to be zeroed Perform zeroing: OK
Figure 7 Zeroing
Do not hold a sensor in the hand, especially a thermal sensor, when
performing a zero adjustment. Temperature effects will influence the
quality of the zeroing result!
When measuring very small power levels dark current of photodiode sensors or zero
voltage on thermal sensors will have an influence on the measurement result and
must be compensated by the zero adjustment. An indicator that a sensor needs to
be zeroed is when with covered sensor either a negative power reading or a reading
much greater than zero is displayed. At negative power readings additionally a
„ZERO!‟ warning appears in the status display.

4.2 Controlling the PM100A
16
After performing a zero adjustment, the detected zero value will be included in all
power readings. The detected zero value may influence the wavelength corrected
calculated full scale power range values in the lower power ranges.
Photodiode sensors emit small current levels, even when no photons hit the active
area –the so called dark current, that is temperature dependent and in the region of
some nA for silicon and InGaAs sensors and up to some µA for germanium sensors.
Thermopile sensors need to be zeroed when thermal differences between active
area (thermal disk) and the sensor heat sink appear when no light hits the active
area or when the heat sink gets hot under light exposure. The zero value will be
negative when the heat sink is hotter than the active area and positive, when the
active area is hotter than the heat sink. When both heat sink and active area are at
room temperature a zero voltage of some µV is normal.
4.2.3.4 Setting an Attenuation / Gain Factor
To set an attenuation or gain factor that will be taken into account when calculating
the displayed power, enter the system menu and navigate to the Attenuation item.
MENU \ Attenuation
When confirming this item with the OK key an attenuation or gain factor from 60 dB
to -60 dB can be entered by the  keys. A positive value will set an
attenuation factor. Confirm the setting with OK and quit the menu by or .
The attenuation set value in dB will be indicated in the status display above the
measurement value.
This feature can be used to display the origin laser or probe power, with having a
filter or beam splitter in the system; or to enlarge the measurement range of a power
or energy sensor with a calibrated filter.
Attenuation set value
Figure 8 Attenuation

4.2 Controlling the PM100A
17
4.2.3.5 Relative Power Measurement
The Δkey switches on and off the relative measurement mode.
The main display will set to zero and gets signed, the offset and the absolute power
value will be displayed in two sub displays in negative presentation. The analog
needle will deflect to the middle position with bidirectional amplitude (0 at the scale
below the mirror) and change to the next sensitive scale.
P = absolute power level P0= offset power level
bidirectional needle
Scale (±100µW)
signed delta power level
Figure 9 Relative Measurement
4.2.4 Display Options
The PM100A can toggle between the standard measurement screen and a statistics
screen by navigating to the MENU item and pressing one of the or keys.
The statistics screen shows the actual, minimum, maximum and average power
level. The HOLD/RUN soft button in the display menu controls this feature. When
the item has focus, the OK button toggles between run and hold mode; in hold
mode, the device samples in the background.
The or key resets all items to the actual power level and restarts sampling.
Ranging during the sampling is possible, though once the actual level exceeds the
measurement range, the stored and calculated values will show „High‟.
Press.
or 
Figure 10 Display Options
Δ

4.2 Controlling the PM100A
18
4.2.5 Sensor Dependent Functions
4.2.5.1 Photodiode Sensors
The PM100A works with all Thorlabs S100C series photodiode power sensors. The
sensor is ready to operate few seconds after plugging to the DB9 connector.
Attention 
Refer to the sensor data sheet and pay attention to the optical
damage threshold!
Exceeding these values will permanently destroy the sensor!
For the measurement of power levels from nano-watts up to 20 W Thorlabs offers
photodiode sensors that show big advantages in sensitivity, stability and drift against
thermal sensors. The sensors are built up in a combination of a photodiode and a
neutral density filter or a photodiode in combination with an integrating sphere. They
provide linearity over several decades and show a very good sensitivity at smallest
power levels down to the pW range. Handling fairly small power levels the sensor
size can be held small, further the response time of such sensors is very fast down
to the sub-microsecond range.
Photodiodes, neutral density filters and also integrating sphere materials show a
wavelength dependent behaviour and therefore each sensor is individually calibrated
over the whole spectral working range in 5 or 10nm steps. Thereby the sensors
spectral response data gets stored in a non-volatile memory inside the DB-9 sensor
connector and downloaded to the PM100A when plugged to the unit. To perform an
accurate measurement it is necessary to enter the operating wavelength of the light
to measure so that the PM100A can calculate the laser power from the measured
photo current and the right response value from the wavelength calibration table.
4.2.5.1.1 Bandwidth Setting (Signal Filtering)
The analogue bandwidth setting influences the power reading and the analogue
output.
The bandwidth can be selected in the system menu under MENU \ Bandwidth.
Confirming the menu item with OK, the bandwidth setting will toggle between „High‟
(range dependent bandwidth up to 100kHz) or „Low‟ (15 Hz bandwidth).
For measuring CW or average power from pulsed sources the bandwidth should be
set to „Low‟. When using the analogue output to control external equipment or