Tunable optical dispersion compensating apparatus
View Patent ↗A tunable optical dispersion compensator (TODC) having a silica arrayed-waveguide grating (AWG) directly coupled at its input to a Mach-Zehnder interferometer device and at its output to a polymer thermo-optic lens.
1. An optical apparatus comprising:
a frequency routing device including an arrayed waveguide grating; and
a Mach-Zehnder interferometer device optically coupled to inputs of said frequency routing device;
CHARACTERIZED IN THAT
the Mach-Zehnder interferometer device includes a pair of arms having lengths of L 1 and L 1 +ΔL 1 respectively; and
the arrayed waveguide grating includes n interconnecting waveguides having lengths of substantially L 2 , L 2 +ΔL 2 , . . . , L 2 +(n−1)ΔL 2 ;
wherein 0.6ΔL 1 <ΔL 2 <1.4ΔL 1 .
2. The optical apparatus of claim 1 wherein said frequency routing device comprises a first slab waveguide and a second slab waveguide and the arrayed waveguides optically interconnecting the first slab waveguide to the second slab waveguide.
3. The optical apparatus of claim 2 wherein said second slab waveguide includes a mirror, positioned at a focal point on a side of the waveguide opposite the grating.
4. The optical apparatus of claim 2 wherein said second slab waveguide includes a lens element, interposed between the mirror and the grating.
5. The optical apparatus of claim 1 wherein said Mach-Zehnder interferometer device includes at least one optical coupler in optical communication with the two arms, said one optical coupler being substantially a 50/50 coupler.
6. The optical apparatus of claim 1 wherein said Mach-Zehnder interferometer device includes at least one optical coupler in optical communication with the two arms, said one optical coupler being substantially a 100/0 coupler.
7. The optical apparatus of claim 1 wherein said Mach-Zehnder interferometer device includes at least one optical coupler in optical communication with the two arms, said one optical coupler being substantially a 0/100 coupler.
8. The optical apparatus of claim 5 wherein said Mach-Zehnder interferometer device includes a second optical coupler in optical communication with the two arms, said second optical coupler being substantially a 100/0 coupler.
9. The optical apparatus of claim 5 wherein said Mach-Zehnder interferometer device includes a second optical coupler in optical communication with the two arms, said second optical coupler being substantially a 0/100 coupler.