Hi.
A RJ45 dongle doing full duplex to LED/photodiode; or a USB that transceives modulating LED light ?
Like to optically link LAN or USB at line of sight within a room over the air ? -No optic fiber involved-

How complex would be to brew one to achieve 100Mb/s ? Visible, IR or UV.

 

You're referring to Free Space Optical Transceivers. AFAIK, USB based ones are not available at present.

Maybe you can lookup https://www.digikey.com/en/articles/techzone/2013/oct/building-free-space-optical-systems

 

Thanks. Yes, free space optical transceivers.
If the led and the photodiode were exposed to room ambient instead of deep inside the fiber connector; would the multipath reflections trash the communication ?

----> http://www.ratioplast.info/index.php/en/productlinie/product/view/163/900

Also, what do you understand by 'RS232' in the product above ?

 

"RS232" is a misnomer. They should have said "UART"

The device uses a fTDI FT232R USB-UART interface chip.

When you plug the dongle into a USB port on your PC, the device enumerates as a serial COM port. You can then perform single character serial communication transfers as you would on a COM port.