The window may be transparent to {TAIL ~ therapeutic wavelengths} transmitted to and through the window and to {HEAD ~ the skin} below 
The window may be transparent to { TAIL ~ therapeutic wavelengths } transmitted to and through the window and to { HEAD ~ the skin } below
OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH