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LIV Test Instrument


What is a Light Current Voltage (LIV) Test?

A light-current-voltage (LIV) test is one of the essential tests that a laser diode must go through to ensure its reliability for post production use. This test will help to verify the operating characteristics of your laser device. The test works by driving current to your laser diode and measuring the resulting voltage and light output. The results are then plotted into a graph, which is known as an “LIV curve”. 

LIV Test Instrument

The Yelo LIV test instrument allows LIV measurements to be taken from laser devices loaded into a Yelo module. This module can also be used with the Yelo Y1000L Low Power Burn-in system. The LIV test instrument has been designed for easy operation. Once powered on, and with laser supply enabled, the touch screen can be used to initiate, monitor and review measurements of laser devices.

For more information please download our brochure or continute to scroll down.



Reduced Operator Handling


  • Measure light and voltage output of laser devices

  • Tests up to 32 laser devices 


  • Can be used as a benchtop or in rack system 

  • 10.1" user friendly touch screen software 


  • Easily set and edit test parameters 

  • Tests TO-56 and Chip on Carrier lasers for 100G Networks  


Set up and edit test recipe's

Easily set and edit the starting current, maximum current, temperature, step delay and step size of the LIV measrements on the user friendly touch screen software. 


Take Measurements without programming

The key benefit of Yelo’s laser diode driver compared to rival products such as Source Measurement Units (SMU’s) is that it allows you to make measurements without programming. You can simply input each element of the LIV test recipe and run your test. It only takes a few seconds.


Pre-test safety feature

The quick pre test feature works as a safety feature. It will run a low current to the laser device to ensure that all connectors are in place and that your full test is safe to run. 

This screen displays the results of the pre-test scan, and indicates whether or not the devices measured forward voltage (VF) was within the set limits. 


Laser Diode Driver Results

The image on the left represents the operating characteristics of the laser diode in; Amps, voltage, ITH (this is the point at which the laser diode starts emitting light), watts and the operating value of quantum efficiency.


Analyse a variety of laser characteristics

Results for all devices will be shown on a graph. Alternatively, you can choose to view the individual results of each laser device. This image represents the voltage and current characteristics of the laser device. Other results such as LIV can also be plotted.

All results can then be saved as a txt file and sent to the Y1000L Burn-in system. 



  • Product: 44.4cm (Front) x 17.6cm (Height) x 40.5cm (Side)

  • Screen: 10.1" touch screen 



  • TO-56

  • Chip on Carrier 

  • Custom Packages
  • Channels: Up to 32 Channels 

  • Temperature range: 25 C - 150 C

  • Max current per device:  Up to 1 Amp


All test data recorded on the LIV Test Instrument can be integrated with Y1000L data. The LIV Test Instrument has been tailored as the ideal solution for pre and post burn-inon laser devices. 




We have aimed to make this the fastest and easiest way possible for users to get their measurements. The user interface has been specifically designed with a clean layout and straightforward set up so that the user can start driving current and testing their laser device as soon as they take it out of the box. No manuals are needed and programming is not necessary.

© Copyright 2019 Yelo Ltd is a registered company in Northern Ireland, registered number NI 16345 VAT No: GB 375 8302 35