摘要:
An optical circulator/isolator (10) is implemented in a semiconductor package formed by a semiconductor substrate (22), which supports integral thin film waveguide polarization splitters and combiners (12, 14), and a semiconductor lid, which supports four spherical lenses (18) and a polarization rotator (16). The latter is a composite of at least two adjacent slabs of optically active material, one slab serving as a nonreciprocal 45° rotator (e.g., a Faraday rotator 16.1) and the other as a reciprocal 45° rotator (e.g., half-wave device 16.2). The lenses, serving both as beam expanders/condensers and as collimators, are positioned between the waveguide ends and major surfaces of the composite slab. When used with means for reversing the of the magnetic field in the nonreciprocal rotator, the device functions also as a switch. Also described are system architectures made possible by these devices; e.g., a single-fiber LAN having a ring architecture for non-interfering counter flow of information and a single fiber, bidirectional FTTH system for handling CATV and POTS. FIG. 1
摘要:
A wavelength selective structure (12) is coupled to an adiabatic Y-coupler (14) via a multimode section (13) which supports both symmetric and antisymmetric modes. One single mode branch (14.1) of the coupler converts guided light to a symmetric mode, whereas the other single mode branch (14.2) converts guided light to an anti-symmetric mode. The structure (12), which includes a pair of single mode waveguide arms (12.1, 12.2) coupled to the common section (13) and a reflection device (20.1, 20.2) (such as a grating or ROR) located in each arm, converts reflected light from a symmetric mode to an anti-symmetric mode and conversely. Applications described include a channel dropping filter and channel balancing apparatus for WDM systems, and a dispersion compensator for fiber optic systems.
摘要:
An optical circulator/isolator (10) is implemented in a semiconductor package formed by a semiconductor substrate (22), which supports integral thin film waveguide polarization splitters and combiners (12, 14), and a semiconductor lid, which supports four spherical lenses (18) and a polarization rotator (16). The latter is a composite of at least two adjacent slabs of optically active material, one slab serving as a nonreciprocal 45° rotator (e.g., a Faraday rotator 16.1) and the other as a reciprocal 45° rotator (e.g., half-wave device 16.2). The lenses, serving both as beam expanders/condensers and as collimators, are positioned between the waveguide ends and major surfaces of the composite slab. When used with means for reversing the of the magnetic field in the nonreciprocal rotator, the device functions also as a switch. Also described are system architectures made possible by these devices; e.g., a single-fiber LAN having a ring architecture for non-interfering counter flow of information and a single fiber, bidirectional FTTH system for handling CATV and POTS. FIG. 1
摘要:
A TE-TM polarization manipulating (i.e., splitting, combining or filtering) device is constructed from substrate-supported dielectric thin film waveguides. In a 3-port device, two waveguides (10,12) have cores (10.1, 12.1) of different materials and different effective refractive indices. The waveguide cores overlap in a first transition section (18) and one waveguide core has an adiabatic taper (12.6); in this section they also separate adiabatically and are coupled to a second (e.g., output) section (16) where the waveguides are physically separate and optically decoupled. In a 4-port device, two additional waveguides are coupled in a second adiabatic transition section to the first transition section to enable TE or TM modes to be coupled straight through the device from one input port to a directly opposite output port or to be crossed-over from one input port to a diagonally opposite output port.
摘要:
A wavelength selective structure (12) is coupled to an adiabatic Y-coupler (14) via a multimode section (13) which supports both symmetric and antisymmetric modes. One single mode branch (14.1) of the coupler converts guided light to a symmetric mode, whereas the other single mode branch (14.2) converts guided light to an anti-symmetric mode. The structure (12), which includes a pair of single mode waveguide arms (12.1, 12.2) coupled to the common section (13) and a reflection device (20.1, 20.2) (such as a grating or ROR) located in each arm, converts reflected light from a symmetric mode to an anti-symmetric mode and conversely. Applications described include a channel dropping filter and channel balancing apparatus for WDM systems, and a dispersion compensator for fiber optic systems.
摘要:
A TE-TM polarization manipulating (i.e., splitting, combining or filtering) device is constructed from substrate-supported dielectric thin film waveguides. In a 3-port device, two waveguides (10,12) have cores (10.1, 12.1) of different materials and different effective refractive indices. The waveguide cores overlap in a first transition section (18) and one waveguide core has an adiabatic taper (12.6); in this section they also separate adiabatically and are coupled to a second (e.g., output) section (16) where the waveguides are physically separate and optically decoupled. In a 4-port device, two additional waveguides are coupled in a second adiabatic transition section to the first transition section to enable TE or TM modes to be coupled straight through the device from one input port to a directly opposite output port or to be crossed-over from one input port to a diagonally opposite output port.