When a beam splitter divides the incoming light, some of the energy is inevitably lost, leading to a decrease in signal strength. If you are trying to set up an external monitor and it's not working, press the Windows logo key + P to make sure that the Extend option is selected. If the Extend option is selected, try the following troubleshooting tips. Disconnect all accessories from your PC. Connected docks, dongles, adapters. They are used to divide a beam of light into two or more separate beams. a laser beam) into two (or sometimes more) beams, which may or may not have the same optical power (radiant flux). It's sensitive to both intensity and frequency. Together, they decide just how accurately an instrument captures those unique infrared “fingerprints” from different substances. It is a crucial part of many optical experimental and measurement systems, such as interferometers, also finding widespread application in fibre optic telecommunications.