6 Direct Femtosecond Laser Writing of Optical Waveguides …
199
Fig. 6.7 3D splitters inscribed in NdYAG based on cladding hexagonal optical-lattice-like structures (Fig. 6.5d). a Schematic of the fabrication technique. b Output modes for 1 × 2 and 1 × 4
splitters. Adapted from [121]
(see Fig. 6.7) can be potentially integrated in any transparent dielectric, thus opening
the way to arbitrarily complex 3D devices in crystals.
6.5.2 Electrooptic Devices
Electrooptic (EO) modulators are used to modulate the signal parameters (e.g., phase,
intensities, and polarizations), which in practice are usually realized in waveguidebased platforms. One of the typical configurations is Mach–Zehnder interferometer
(MZI), which was produced in laser-written LiNbO 3 waveguides. Liao et al. reported
on a MZI waveguide modulator produced by femtosecond laser inscription in a xcut MgO:LiNbO 3 wafer [86]. This structure was composed of channel waveguides
199
Fig. 6.7 3D splitters inscribed in NdYAG based on cladding hexagonal optical-lattice-like structures (Fig. 6.5d). a Schematic of the fabrication technique. b Output modes for 1 × 2 and 1 × 4
splitters. Adapted from [121]
(see Fig. 6.7) can be potentially integrated in any transparent dielectric, thus opening
the way to arbitrarily complex 3D devices in crystals.
6.5.2 Electrooptic Devices
Electrooptic (EO) modulators are used to modulate the signal parameters (e.g., phase,
intensities, and polarizations), which in practice are usually realized in waveguidebased platforms. One of the typical configurations is Mach–Zehnder interferometer
(MZI), which was produced in laser-written LiNbO 3 waveguides. Liao et al. reported
on a MZI waveguide modulator produced by femtosecond laser inscription in a xcut MgO:LiNbO 3 wafer [86]. This structure was composed of channel waveguides