cancel
Showing results for 
Search instead for 
Did you mean: 

VL53L4CX VCSEL optical power

CTrestino
Associate

For a medical device that use NIR light we are using the VL53L4CX as range detector. We found that the TOF sensor light interfere with our NIR lighting system. In order to perform some simulations we would like to have some more details about the light irradiance from the sensor VCSEL. From datasheet we found only few data related to the wavelength. Is it possible to have some more detailed applicaiton notes and/or datasheet related to the VCSEL of the TOF.

BR

 

3 REPLIES 3
John E KVAM
ST Employee

The VCSEL is spec'ed to be 940nm. But it also has a pulse repetition period. 

In 'short mode', the VCSEL is on for 2 nano seconds, then off, then on again. 

It looks like this:

JohnEKVAM_0-1747678462462.png

But the frequency does change a bit with temperature:

JohnEKVAM_1-1747678573762.png

 

But I'm going to assume in a medical setting the temperature is reasonably well regulated. So maybe 939nm. 

One should note that the pulse repetition rate does change. There are actually 2 of them. But having two different rates we can detect something call radar aliasing. 

 


If this or any post solves your issue, please mark them as 'Accept as Solution' It really helps. And if you notice anything wrong do not hesitate to 'Report Inappropriate Content'. Someone will review it.

Dear John,

 thanks for the very usefull information.

It would be very useful to be able to get some more information with respect to the irradiance of the VCSEL transmitter. I have to estimate  the intensity at 1 meter distance.

 

Thanks

Cosmo

Zhiyuan.Han
ST Employee

Hi,

Please find below VCSEL power data for L4. 

 

ZhiyuanHan_1-1750299678666.png

Br

Zhiyuan.Han


In order to give better visibility on the answered topics, please click on 'Accept as Solution' on the reply which solved your issue or answered your question.