OPTICAL DATA COMMUNICATION

摘要

An optical communication system (1) comprises a transmitter (2), a multi-core fibre bundle cable assembly (3), and a receiver (4). The transmitter (2) consists of a laser driver integrated circuit (5) which is used to modulate a light source (6), the light 7 from which is coupled through a lens (8) which provides a substantially collimated output beam (9) which is parallel or nearly so and has a beam diameter in the region of 100 µm to 150 µm. The fibre cable assembly (3) comprises a multi-core fibre bundle. The individual fibre cores (24, 25 and 26) have core diameters in the region of 100 µm. This arrangement provides that the coupling efficiency of light from the transmitter 2 into the fibre bundle assembly 3 is insensitive to a significant level of lateral and axial misalignment between the fibre bundle cable assembly 3 and the transmitter 2. For this embodiment an acceptable coupling efficiency can be maintained for a lateral misalignment of at least ± 100 µm and axial misalignment of greater than 1000 µm. The receiver (4) comprises a spherical lens (27) configured to collect light (22) emitted from the entire facet of the multi-core fibre bundle cable assembly (3) and focus the light onto a light detector (28). Light may be coupled in varying proportions into all of the cores of the fibre bundle (3). The light 22 emitted from the fibre bundle facet has a low divergence angle, achieved by the combination of the collimation and fibre bundle short length (< 2m) despite the individual fibres of the bundle 3 having a numerical aperture of 0.5 or greater.