Optical module for terabit switch

Abstract

A switch module includes a switch integrated circuit (IC), a photonic integrated circuit (PIC), and a planar lightwave circuit (PLC). The PIC may include a plurality of light sources, an optical splitter, and a plurality of modulators. A dual MEMS may be used to align lens arrays, which may be used to couple light from the PIC to the PLC.

What is claimed is: 
     
         1 . A switch module, comprising:
 a switch integrated circuit (IC) chip including a switch for routing inputs to outputs of the switch IC chip;   a photonic integrated circuit (PIC) comprising:
 a plurality of light sources for providing light; 
 an optical splitter having a plurality of inputs and outputs and for use in splitting the light provided by each of the plurality of light sources; and 
 a plurality of modulators for modulating light received from the plurality of outputs of the optical splitter and for providing modulated optical signals; 
   a planar lightwave circuit (PLC) optically coupled to the PIC and positioned to receive the modulated optical signals, the PLC configured to combine the modulated signals into an optical output (or multiple outputs);   wherein outputs of the switch IC chip are coupled to the plurality of optical outputs.   
     
     
         2 . The switch module of  claim 1 , wherein the PIC further comprises semiconductor optical amplifiers (SOAs), each of the SOAs coupled to one of the plurality of modulators and positioned along a path of the one of the plurality of modulators. 
     
     
         3 . The switch module of  claim 1 , wherein the plurality of light sources may be oriented perpendicular to the plurality of modulators. 
     
     
         4 . The switch module of  claim 1 , wherein the PLC includes arrayed waveguide gratings (AWGs) and waveguides for routing the AWGs. 
     
     
         5 . The switch module of  claim 4 , wherein the bends comprise silicon nitride material. 
     
     
         6 . The switch module of  claim 1 , wherein only one of the plurality of light sources is activated at any given time. 
     
     
         7 . The switch module of  claim 1 , wherein the optical splitter is a multimode interference (MMI) coupler, or a star coupler. 
     
     
         8 . The switch module of  claim 1 , wherein the plurality of light sources comprise lasers. 
     
     
         9 . The switch module of  claim 1 , wherein the plurality of modulators comprise Mach-Zehnder, electro-absorption and plasma effect modulators. 
     
     
         10 . The switch module of  claim 1 , wherein the plurality of light sources comprise redundant lasers. 
     
     
         11 . The switch module of  claim 2 , wherein each of the SOAs is positioned before or after the one of the plurality of modulators. 
     
     
         12 . The switch module of  claim 1  further comprising microstrip lines routed along a surface of the PLC for conveying electrical signals from the PLC to a transimpedance amplifier (TIA). 
     
     
         13 . The switch module of  claim 1 , wherein the coupling of the PLC to the PIC is performed using MEMS, the MEMS configured to hold and align an array of lenses and including a holder for holding the array of lenses, the holder coupled to first, second, third, and fourth adjustment arms. 
     
     
         14 . The switch module of  claim 13 , wherein the first and second arms are manipulable so as to move the holder about an x-axis and the third and fourth arms are manipulable so as to move the holder about a y-axis. 
     
     
         15 . The switch module of  claim 1 , wherein one or more PLCs can couple with multiple PICs using a MEMs device to align the lens array to couple the light between them. 
     
     
         16 . The MEMS device of  claim 13 , wherein a secondary spring to release torsion stress when an opposing arm is moved. 
     
     
         17 . A switch module, comprising:
 a plurality of photonic integrated circuit (PICs), each of the PICs comprising a plurality of light sources for generating light, an optical splitter having inputs and outputs and configured to split light generated by each of the plurality of light sources, and a plurality of modulators, with each of the plurality of modulators configured to modulate light provided by one of the outputs of the optical splitter and to generate a modulated optical signal;   a single layer or a plurality of stacked planar lightwave circuit (PLCs) optically coupled to the PICs and configured to combine modulated optical signals from the plurality of modulators into an optical signal.   
     
     
         18 . The switch module of  claim 17  further comprising an optical connector for forming optical connections between the plurality of stacked PLCs and optical fibers, the optical connector including a lens array having various rows and configured to pass light between the plurality of stacked PLCs and the optical fibers. 
     
     
         19 . The switch module of  claim 18 , wherein the single layer of PLC has no vertical stack and the lens array is a single row of four lenses. 
     
     
         20 . The switch module of  claim 18 , wherein the plurality of stacked PLCs are two vertically stacked PLCs and the lens array includes two rows of lenses with four lenses per row. 
     
     
         21 . The switch module of  claim 18 , wherein the plurality of stacked PLCs are four vertically stacked PLCs and the lens array includes four rows of lenses with four lenses per row. 
     
     
         22 . The switch module of  claim 17 , wherein a surface of the single layer or each of the plurality of stacked PLCs is coupled to microstrip or CPW transmission lines, the microstrip or CPW transmission lines configured to convey electrical signals from each of the PLCs to a transimpedance amplifier (TIA). 
     
     
         23 . The switch module of  claim 21 , wherein the microstrip or CPW transmission lines include 32 transmission lines.