Is there an electronic device that detects EM waves while allowing them to pass through? kind Kind of like a window that can detect a measure the qualities/quantities of a light ray but lets it pass through to other devices or similar? I have no idea of what of keywords/phrase to use to even search this kind of device. I made a diagram incasein case for better understanding. 
Question about the existence Existence of a certain type of optoelectronic device that detects EM waves while allowing them to pass through?
Question about the existence of a certain type of optoelectronic device that detects EM waves while allowing them to pass through?
Is there an electronic device that detects EM waves while allowing them to pass through? kind of like a window that can detect a measure the qualities/quantities of a light ray but lets it pass through to other devices or similar? I have no idea of what of keywords/phrase to use to even search this kind of device. I made a diagram incase for better understanding. 
Thanks in advance.
Existence of a certain type of optoelectronic device that detects EM waves while allowing them to pass through?
Is there an electronic device that detects EM waves while allowing them to pass through? Kind of like a window that can detect a measure the qualities/quantities of a light ray but lets it pass through to other devices or similar? I have no idea of what of keywords/phrase to use to even search this kind of device. I made a diagram in case for better understanding.
Question about the existence of a certain type of optoelectronic device that detects EM waves while allowing them to pass through?
Is there an electronic device that detects EM waves while allowing them to pass through? kind of like a window that can detect a measure the qualities/quantities of a light ray but lets it pass through to other devices or similar? I have no idea of what of keywords/phrase to use to even search this kind of device. I made a diagram incase for better understanding. 
Thanks in advance.