High-Speed, Large-Area POF Receivers for Fiber Characterization and Data Transmission $\geq$ 10-Gb/s Based on MSM-Photodetectors

The authors report on high-speed, very large-area, visible light photoreceivers suitable for large-core 1 mm polymer optical fibers (POF). The receivers are based on metal-semiconductor-metal photodetectors (MSM-PD) grown on gallium-arsenide (GaAs) substrate. Three active diameters of Ø1000 μm, Ø700 μm and Ø400 μm were fabricated in order to meet the requirements of the following three specific POF applications. The first photoreceiver was designed to characterize the bandwidth of 1 mm POF. For that reason the receiver has an active diameter of Ø1000 μm to detect all modes at the end of the fiber. With this receiver the frequency response of 1 mm graded-index (GI-) POF was measured up to 12 GHz. The Ø700 μm photoreceiver was designed for high-speed data transmission. Due to the large active area there is no need for an optical concentrator and the 1 mm POF can simply be butt-coupled to the receiver. With this receiver a novel real-time transmission of 10 Gb/s over up to 20 m GI-POF using simple non return to zero (NRZ) modulation is presented. For data rates beyond 10 Gb/s the Ø400 μm photoreceiver with a 3-dB bandwidth of 11 GHz was designed. A record bit rate of 32 Gb/s was transmitted with this receiver over large-core 1 mm polymethylmethacrylate (PMMA) GI-POF. These achieved results are by far the best reported values for large-area visible light photoreceivers.