The authors demonstrate the first ion-exchanged, planar lossless split
ter at 1.5 mu m. The 1 x 2 device was fabricated by thallium ion excha
nge in an Er/Yb codoped borosilicate glass, and achieved lossless spli
tting over the wavelength range 1534-1548nm when pumped with a 980nm l
aser diode.