In optical interconnection technology, high-speed and large data transitions with low error rate and cost reduction are key issues for the upcoming 8K media era. The researchers present notable types of optical manufacturing structures of a four-channel parallel optical module by fully passive alignment, which are able to reduce manufacturing time and cost. Each of the components, such as vertical-cavity surface laser/positive-intrinsic negative-photodiode array, microlens array, fiber array, and receiver (RX)/transmitter (TX) integrated circuit, is integrated successfully using flip-chip bonding, die bonding, and passive alignment with a microscope. Clear eye diagrams are obtained by 25.78-Gb/s (for TX) and 25.7-Gb/s (for RX) nonreturn-to-zero signals of pseudorandom binary sequence with a pattern length of 231 to 1. The measured responsivity and minimum sensitivity of the RX are about 0.5 A/W and ≤−6.5 dBm at a bit error rate (BER) of 10−12, respectively. The optical power margin at a BER of 10−12 is 7.5 dB, and cross talk by the adjacent channel is ≤1 dB.
We propose a novel, low-cost bidirectional optical subassembly (BOSA) that uses a single glass-sealed conventional transistor-outline (TO)-CAN package for passive optical network application. In this BOSA, optical transmitting and receiving functions are incorporated into a silicon optical bench and in a TO-CAN package, respectively. With these features, the optical and electrical crosstalk is efficiently suppressed. The single TO-CAN BOSA has an extinction ratio of 11.69 dB and output power of 2.93 dBm for 1.25 Gb/s operation. The penalty of optical dispersion is 1.2 dB after 20-km single-mode fiber transmission. The receiver sensitivity is less than −30 dBm at a bit error rate of 10−3 for 10.3 Gb/s operation and the signal crosstalk penalty of a single TO-CAN BOSA is 0.8 dB.
A dual-wavelength optical subassembly (OSA) using a typical glass-sealed transistor outline-can (TO-CAN) package is presented. The proposed OSA has a simple structure and is sufficiently compact to integrate two optical channels in a single TO-CAN package. And the proposed OSA realizes the reduction in cost by reducing the number of parts and the laser welding process. The measurement results of 3 dB of bandwidth of the proposed dual-wavelength OSA are more than 4.5 GHz for transmitter module and more than 4.0 GHz for receiver module. The clear eye diagrams with more than 8.6 dB of the extinction ratio and less than −24.5 dBm of receiver minimum sensitivity at a bit error rate of 10−10 are obtained under 2.5 Gbit/s operations.
Tilted fiber Bragg grating can couple light both to backward propagating core modes and cladding modes. We propose a WDM receiving device with high cladding and/or radiation mode coupling efficiency using etched cladding parts and tilted Fiber Bragg gratings(TFBGs) which are key components for doing wavelength selective operations. Each channel exhibits the cladding and radiation mode coupling efficiency of approximately 20%.