BOARD-TO-BOARD FREE-SPACE OPTICAL INTERCONNECTIONS PASSING THROUGH BOARDS FOR A BOOKSHELF-ASSEMBLED TERABIT-PER-SECOND-CLASS ATM SWITCH

We propose free-space optical interconnections fbr a bookshelf-assembl ed terabit-per-second-class ATM switch. Thousands of arrayed optical b eams, each having a rate of a few gigabits per second, propagate verti cally to printed circuit boards, passing through some boards, and are connected to arbitrary transmitters and receivers on boards by polariz ation controllers and prism arrays. We describe a preliminary experime nt using a 1-mm-pitch 2 x 2 beam-collimator array that uses vertical-c avity surface-emitting laser diodes. These optical interconnections ca n be made quite stable in terms of mechanical shock and temperature fl uctuation by the attachment of reinforcing frames to the boards and us e of an autoalignment system. (C) 1998 Optical Society of America.