Investigation of Refractive Index Profile Induced with Femtosecond Pulses into Neodymium Doped Phosphate Glass for the Purposes of Hybrid Waveguiding Structures Formation

The technique of writing depressed cladding waveguides into Nd:phosphate glass with relatively large mode field diameter in 2-line geometry was reported for the purposes of waveguiding structures formation. The easy to use and accurate technique of induced refractive index measurement was proposed, and it was shown the inefficiency of widespread indirect (numerical aperture) technique of refractive index measurement for such femtosecond written waveguides.