pyThorlabsPM100x

pyThorlabsPM100x is a Python library/GUI interface to control the Thorlabs consoles PM100A and PM100D. The package is composed of two parts, a low-level driver to perform basic operations, and high-level GUI, written with PyQt5, which can be easily embedded into other GUIs.

Table of Contents

• Installation
• Usage via the low-level driver
  • Examples
• Usage as a stand-alone GUI interface
• Embed the GUI within another GUI

Installation

Use the package manager pip to install,

pip install pyThorlabsPM100x

This will install pyThorlabsPM100x together with all libraries required to run the low-level driver. In order to use the GUI, it is necessary to install additional libraries, specified in the requirements.txt files,

pip install abstract_instrument_interface>=0.6
pip install "PyQt5>=5.15.6"
pip install "pyqtgraph>=0.12.4"
pip install numpy

Important: in order to be accessible from this library, the console needs to be set to "PM100D NI-VISA" modality, and not to "TLPM modality". Typically, if you used recent Thorlabs software to acquire from a console, that will automatically set the console to "TLPM modality". You can use the utility Power Meter Driver Switcher to switch between modalities.

Usage via the low-level driver

pyThorlabsPM100x provides also a low-level driver, based on the library pyvisa, to directly interface with the powermeter console.

from pyThorlabsPM100x.driver import ThorlabsPM100x
powermeter = ThorlabsPM100x()
available_devices = powermeter.list_devices()
print(available_devices)
powermeter.connect_device(device_addr = available_devices[0][0])
print(powermeter.power)
powermeter.disconnect_device()

The method list_devices() returns a list, with each element representing one available device in the format [address,identity,model]. The string address contains the physical address of the device. The line powermeter.connect_device(device_addr = available_devices[0][0]) establishes a connection to the first device found. We then print the power currently read by the console, and finally disconnect from it.

The class ThorlabsPM100x supports several properties and methods to communicate with the console and to read/change its settings. Some of the properties are read-only, while others can be set. A full list of properties and methods is available here below

Properties

Property	Type	Description	Can be set?	Notes
power	(float,str)	First element of list is the power currently read by the console, second element is the power units.	No
power_units	str	Power units	No
wavelength	int	Operating wavelength (in nanometers) of the console.	Yes	Each powermerter head has a different range of acceptable wavelengths. The driver will not return an error when trying to set a wavelength outside of this range.
power_range	float	Current power range, defined as the maximum power measurable in the current range	Yes	When setting this property to a particular value X, the console will change the power range to the smallest power range which allows to measure the desired power X.
min_power_range	float	Minimum power range available.	No	For the same console/head, this value might vary for different wavelengths.
max_power_range	float	Maximum power range available.	No	For the same console/head, this value might vary for different wavelengths.
auto_power_range	bool	Determines whether the consol is in auto power range or not.	Yes
being_zeroed	bool	It is True if zero of the device is currently being set.	No	The property power will return (None,'') if read while being_zeroed==True

Methods

Method	Returns	Description
list_devices()	list	Returns a list of all available devices. Each element of the list identifies a different device, and it is a three-element list in the form [address,identity,model]. The string address contains the physical address of the device. The string idn contains the 'identity' of the device (which is the answer of the device to the visa query '*IDN?'). The string model contains the device model (either 'PM100A' or 'PM100D').
connect_device(device_addr: str)	(str,int)	Attempt to connect to the device identified by the address in the string device_addr. It returns a list of two elements. The first element is a string containing either the ID number of the connected device or an error message. The second element is an integer, equal to 1 if connection was succesful or to 0 otherwise.
disconnect_device()	(str,int)	Attempt to disconnect the currently connected device. If no device is currently connected, it raises a RuntimeError. It returns a list of two elements. The first element is a string containing info on succesful disconnection or an error message. The second element is an integer, equal to 1 if disconnection was succesful or to 0 otherwise.
read_min_max_wavelength()	(float,float)	Returns the minimum and maximum operating wavelengths for the connected device. If no device is currently connected, it raises a RuntimeError.
set_zero()	int	Set the zero to the currently connected (if any) console. The returned value is 1 if the operation was successful, or 0 if any error occurred.
move_to_next_power_range(direction: int)	None	It increases or decreases the power range of the console, depending on whether the input parameter is direction=+1 or direction=-1.

Examples

from pyThorlabsPM100x.driver import ThorlabsPM100x
powermeter = ThorlabsPM100x()
available_devices = powermeter.list_devices() #Check which devices are available
print(available_devices)
powermeter.connect_device(device_addr = available_devices[0][0]) #Connect to the first available device
print(powermeter.power) #print the power currently read
print(powermeter.wavelength) #print the operating wavelength
(minWL,maxWL) = powermeter.read_min_max_wavelength() #read max and min available wavelengths
powermeter.wavelength = maxWL #set wavelength to the max
print(powermeter.power_range) #print current power range
powermeter.move_to_next_power_range(direction=+1) #increaase power range
print(powermeter.power_range) #print new power range
powermeter.disconnect_device() #disconnect the device

Usage as a stand-alone GUI interface

The installation should set up an entry point for the GUI. Just typing

pyThorlabsPM100x

in the command prompt will start the GUI.

Embed the GUI within another GUI

The GUI controller can also be easily integrated within a larger graphical interface, as shown in the example here.