An asymmetric Y-junction wavelength demultiplexer, with a segmented branch, was realized in Ti:LiNbO3. The device was fabricated in a single-step lithographical process. Wavelength demultiplexing operation in the range 633 nm<λ<834 nm is demonstrated, with extinction ratios up to 30 dB. Insertion loss vary between a negligible value (far away from cutoff) up to 7 dB (near cutoff). Possible applications of the device are considered.