Power Meters FAQ's

Laser Power Meters



In all Ophir instruments, all adjustments, including zeroing internal circuits, are done from the software. This ensures simple and accurate realignment. The zeroing process helps eliminate internal biases in the unit which could affect accuracy of measurements. It is recommended to re-zero the instrument every 2 months for best performance. Specific instructions for doing this are found in the relevant User Manual for each instrument.


For the best accuracy and repeatability, each Ophir meter should be zeroed with no sensor connected periodically. It would not hurt to zero the meter each time it is used, but we recommend to zero the meter at least once a month. See your meter User Guide for the zeroing procedure particular to your meter. To view or download a copy of the meter User Guides, follow this link: https://www.ophiropt.com/laser-measurement-instruments/laser-power-energy-meters/services/manuals.



Select the range that contains your wavelength. The sensors have coatings on them that have been characterized and for any wavelength within that range the sensor will be within calibration tolderance including variations in sensitivity within that range. When there is a difference in sensitivity that exceeds the allowable tolerances, a new wavelength range is created and a calibrated for.


Ophir hand held displays are shipped with a 2-conducter 2.5mm mono audio jack connector that you can plug into the top of the display to get the analog signal out of the display. You will need to solder your own cable onto the connector.


Think of it like a voltmeter or ammeter, these have to be recertified/recalibrated as well like most other pieces of test equipment. In general, our instruments are unlikely to drift or fail over time like a sensor might that is constantly exposed to laser energy. But the possibility exists. So the general practice in our industry is to have Power and Energy Meterss recalibrated and recertified as well. ISO standards and FDA, as well as other agencies, require both be recalibrated and recertified.


If the firmware programming procedure doesn’t complete, you should be able to recover and reprogram the StarLite firmware.

  • Make sure to completely power down the StarLite, as is mentioned in the StarLite Upgrade Tool screen instructions (long press On/Off button).
  • If unsure that StarLite has really shut down, it’s advisable to try disconnecting the USB cable and then power down the StarLite.
  • Reconnect the USB cable.

Then proceed (again) with the StarLite Field Upgrade Tool: Turn StarLite on in the special ‘burn-in’ mode by pressing the two button combination as detailed in the onscreen instructions, (you should hear from the PC speakers the ‘ding dong’ tone associated with a device being connected to the PC), and then continue the steps as prompted. If problems continue, please contact Ophir-Spiricon Service at service@us.ophiropt.com.


All Ophir meters use a 12 bit A-to-D, however the output range given is about 10% above the 100% level and also 10% below the zero level. In actuality this give 11.5 bits resolution between 0% and 100%.


  Vega Nova II Nova Laserstar StarBright StarLite
resolution 11.5 bit 11.5 bit 11.5 bit 11.5 bit 11.5 bit 11.5 bit
update rate/s 15 15 15 15, 25/s for pyro sensors 15 15



The latest firmware for all meters except the Nova includes the ability to automatically read different sensor information, when it is connected, without the requirement to power the meter Off an On again.

Some of the older software versions require you to turn the meter off and on to register the new sensor.

The latest firmware for the upgrading the meters is available at;



The analog output of the meter - using the mating connector provided – gives a voltage signal proportional to the actual reading (it is in fact just a D/A translation of what is being displayed), so it represents a fully calibrated reading. The full scale value is a function of the meter being used and the power range it is on. With the StarBright, Vega and Nova II, for example, the user can select full scale analog output voltage ranges of 1v, 2v, 5v or 10v, and the 100% level of the chosen power scale is scaled to the full scale voltage. For example: if you choose 5V full scale analog voltage range, and your sensor is set to a 50W full scale power range, then you will have 5V = 50W or 0.1 V/W. It will vary according to the chosen power range and chosen full scale voltage range. The electrical accuracy is stated in the specification (see the User manual) as ±0.2% (of reading) ±0.3% of full scale volts (in addition to the calibration accuracy of the sensor’s reading itself).


The choice of meter depends on what range of functionality you need (unlike the choice of sensor, which depends on the technical, physical parameters of the laser). Just to give a quick general idea:

  • For just basic measurements, no graphics or analysis, and/or when budget is tight, the StarLite is a good choice.
    • If you might want to connect your StarLite to a PC, getting the StarLite with the USB Enabling added will allow you to connect to a PC with the "StarLab" laser measurement application running.
  • For a solid set of functions, perhaps onboard logging, things like Density, Limits etc, then Vega
  • For higher capabilities, combined functions, graphic display options, etc, then StarBright
  • For working only connected to a PC (as opposed to also working stand-alone), a PC interface such as Juno

You may find our Meter Finder very helpful - a detailed comparison table of features and capabilities of the various Ophir instruments. And, needless to say – feel free to ask Ophir for help!


The sensors with a continual response curve such as the ones listed above come with preset "favorite" wavelengths. If these "favorite" wavelengths do not match the application wavelength you are using they can be changed by performing the instructions below, which are for the Vega meter. For your specific meter, please see the User Manual.

  • While the Vega is off, plug in the head. Switch on the Vega.
  • From the main measurement screen, press "Laser" to select the correct laser wavelength. If you want to save this new wavelength as the startup default, press "Save" before exiting. If the wavelength you want is not among the wavelengths in the six wavelengths listed and you want to change or add a wavelength, see the next step
  • Changing Chosen Wavelengths:
    • From the power measurement screen select "Laser" and enter. Move to the wavelength you wish to change or add. Press the right navigation key.
    • Using the up/down keys to change each number and the right/left keys to move to the next number, key in the desired wavelength. Press the Enter key to exit. If you wish to save this new wavelength as one of the 6 favorite wavelengths, press "Save".

Note: Saving the new wavelength in the Modify screen will not set this wavelength as the default startup wavelength. To do so, you must follow the instructions in Step 2 above.