Hollow light guide

Patent Granted A prism light guide was developed in 1981 by Lorne Whitehead, a physics professor at the University of British Columbia[18][19] and has been used in solar lighting for both transport and distribution of light.[20][21] A large solar pipe based on the same principle has been set up in a narrow courtyard of a 14-floor building of a Washington D.C. law firm in 2001,[22][23][24][25][26] and a similar proposal has been made for London.[27] A further system has been installed in Berlin.