Optical power meter, how do we use one?
An Optical power meter is used when you wish to ensure
Optical power is expected to be well controlled.
It is recommended by the experts that the optical power should not be too low or too high.
The recommendation is to be within the scope of the given instrument.
For achieving the accurate measurement of the optic power, the device named Optical Power Meter (OPM) is
This device helps in testing the optical power of the
However, the question arises, “How do we use the OPM?”
In this post, we will help you understand how to use the optical power meter effectively.

Understanding the Optical Power Meter Buttons
The overall operations, as well as functions of the OPM device that are provided by different manufacturers in the market, tend to be quite similar.
Typically, the OPM device is known to feature four buttons, including the following:
- dBm/w button
- power button
- wavelength button
- REF button
Some functions of our Yamasaki Optical Power Meter buttons are listed below:
- Power button –for turning the OPM device on & off
- Wavelength button –for selecting the calibrated wavelength. Some of the most common wavelengths are 850nm, 1300nm,1310 nm, 1550nm & 1625nm
- Backlight control
- Save to save your records
- DEL to delete your records
- Units – dBm/w button –for shifting between the logarithmic (dBm) mode and linear (mW) mode
- REF to set your reference

Optical Power Meter Keypad
Optical Power Meter Adapter Type
For using the OPM device, a specific length of patch cable is typically required for connecting to the OPM interface.
This is then also connected to the interface of the multiple devices that require testing.
For example, if the interface of the OPM device tends to be FC and the device being tested has an LC interface, you would require an FC-LC length of

OPM devices tend to feature a fixed optical interface.
Some of the devices are also capable of providing replaceable adapters of the OPM device for allowing you to fit various patch cables.
An OPM device can also feature two optical interfaces for the most common connectors available.
However for specific interfaces like MTP/MPO, it is recommended to use an OPM device with a special interface.
OPM for Optical Power Measurement
When you are looking for answers to how to use the OPM, you should also be looking at how to use the device for measuring the optical power at the same time.
Taking an example of the 10G-LR SFP+ along with the Cisco-compatible module, we will help in illustrating how you should use the optical power meter for testing the optical power.
The Cisco-compatible transceiver is typically inserted into the Cisco switch of the model Nexus 9396PX.
Optical Power Measurement
A single-mode LC-FC
This is because the transceiver of the model 10G-LR SFP+ tends to be an LC single-mode transceiver that works at the wavelength value of 1310 nanometer.

Once the OPM device has been connected to the given module, you are required to switch on the power button.
Then you need to press the wavelength button to select the wavelength value of 1310nm.
Initially, the power value might alter rapidly, then it will slow down gradually until it becomes still.
The value for the final optical power will be displayed on the respective screen.
Conclusion
The functions of a power meter are there to assist the user in getting result. Allowing the user to interact with the device.
The user can choose wavelength and set the reference.
You can then save and store the reading and download to your PC at your leisure making it the ideal instrument to use for testing power.
For more information on testing please click on the link to our blog below