The present invention provides for a polarization independent optical switch for selectively switching an optical signal from at least one input port to a preselected one of a plurality of different output ports. The optical switch operates to transmit all of the optical signal from an input port to a predetermined one of the output ports without first segmenting the optical signal into two polarizations.

A reflecting-type optical switch is constructed by stacking a parallel plate-shaped glass substrate and a parallel plate-shaped polarization controller, providing a reflecting portion in such a manner that incident light propagates in zigzag fashion owing to reflection, and depositing a polarizing separating film on the glass substrate where two prescribed incident light beams intersect owing to reflection. Further, a transmission-type optical switch is constructed by providing a polarization controller in front of a polarizing prism, and depositing a polarizing separating film on the glass substrate of the polarizing prism where two prescribed incident light beams intersect owing to reflection. Furthermore, an optical distributor is constructed by stacking a plurality of parallel plate-shaped glass substrates and depositing a partial reflecting film on the glass substrate where two prescribed incident light beams intersect owing to reflection.

The switching method is constituted with a novel nonblocking routing optical crossbar network system. It includes two parts: one is a routing fan-out unit which provides N parallel optical channels for each of M input light beams, and the other is a routing combination unit in which M parallel optical channels that have the same output port, are routing combined into one optical parallel channel of N parallel output channels by the routing fan-in network. According to the method of the present invention, the optical module of M.times.N (M=2.sup.m, N=2.sup.n, m and n are nature numbers) routing matrix switching can be developed.

A system and method of providing a periodic trajectory scan path for a laser beam across a photoconductive surface in a laser printer. A preferred embodiment of the periodic trajectory for a system with a two-axis deflector includes a multiple-frequency omega wave trajectory for providing a substantially rectangular grid of available dot locations for selective laser beam pulsing. As such, a plurality of generally linear rows of dots are completed in a single scan pass of the laser beam across the surface. The periodic trajectory is provided by deflecting the laser beam with an optical beam deflector, such as an electro-optic deflector, placed between the laser and the rotating polygon scanning mirror. A preferred embodiment of the beam deflector includes a folded optical path.

A method of assembling an optical device for coupling optical fibers to a corresponding number of input/output ports of a stack of optical elements includes utilizing at least one controllable multi-state optical element to selectively switch the optical coupling among the ports. The controllable multi-state element is one element within a stack of polarization-manipulating elements having a configuration that allows the condition of the multi-state element or elements to dictate the optical coupling among the ports. In the preferred embodiment, the multi-state element is a Faraday rotator. The method may be used in either or both of a quality control application or a fiber-to-port alignment application. In the quality control operation, the stack of polarization-manipulating elements is tested to verify proper operation with respect to separating and selectively recombining polarization components of input beams. In the fiber-to-port alignment application, the fibers on the same side of the stack are first fixed in a parallel relationship with a known center-to-center distance that is equal to the center-to-center distance between corresponding ports of the stack. By optically aligning one of the fibers on the forward side of the stack with the fibers on the rearward side of the stack, at least one other fiber is automatically brought into registration with its corresponding port.