All-optical majority gate based on an injection-locked laser

An all-optical computer has remained an elusive concept. To construct a practical computing primitive equivalent to an electronic Boolean logic, one should utilize nonlinearity that overcomes weaknesses that plague many optical processing schemes. An advantageous nonlinearity provides a complete set of logic operations and allows cascaded operations without changes in wavelength or in signal encoding format. Here we demonstrate an all-optical majority gate based on a vertical-cavity surface-emitting laser (VCSEL). Using emulated signal coupling, the arrangement provides Bit Error Ratio (BER) of 10(-6) at the rate of 1 GHz without changes in the wavelength or in the signal encoding format. Cascaded operation of the injection-locked laser majority gate is simulated on a full adder and a 3-bit ripple-carry adder circuits. Finally, utilizing the spin-flip model semiconductor laser rate equations, we prove that injection-locked lasers may perform normalization operations in the steady-state with an arbitrary linear state of polarization.Peer reviewe

Simultaneous wavelength and orbital angular momentum demultiplexing using tunable MEMS-based Fabry-Perot filter

In this paper, we experimentally demonstrate simultaneous wavelength and orbital angular momentum (OAM) multiplexing/demultiplexing of 10 Gbit/s data streams using a new on-chip micro-component – tunable MEMS-based Fabry-Perot filter integrated with a spiral phase plate. In the experiment, two wavelengths, each of them carrying two channels with zero and nonzero OAMs, form four independent information channels. In case of spacing between wavelength channels of 0.8 nm and intensity modulation, power penalties relative to the transmission of one channel do not exceed 1.45, 0.79 and 0.46 dB at the harddecision forward-error correction (HD-FEC) bit-error-rate (BER) limit 3.8 × 10¯³ when multiplexing a Gaussian beam and OAM beams of azimuthal orders 1, 2 and 3 respectively. In case of phase modulation, power penalties do not exceed 1.77, 0.54 and 0.79 dB respectively. At the 0.4 nm wavelength grid, maximum power penalties at the HD-FEC BER threshold relative to the 0.8 nm wavelength spacing read 0.83, 0.84 and 1.15 dB when multiplexing a Gaussian beam and OAM beams of 1st, 2nd and 3rd orders respectively. The novelty and impact of the proposed filter design is in providing practical, integrable, cheap, and reliable transformation of OAM states simultaneously with the selection of a particular wavelength in wavelength division multiplexing (WDM). The proposed on-chip device can be useful in future high-capacity optical communications with spatial- and wavelengthdivision multiplexing, especially for short-range communication links and optical interconnects

26-Gb/s DMT Transmission Using Full C-Band Tunable VCSEL for Converged PONs

Wavelength division multiplex (WDM) passive optical network (PON) is considered for converged fixed mobile broadband access networking. We propose to utilize low-cost tunable lasers at the remote sites, together with a centralized wavelength locker. Practical implementations require a transparently added downstream signaling channel and upstream per-channel pilot tones for channel tagging and remote wavelength control. We demonstrate, for the first time, 26-Gbps discrete multitone transmission modulated on a low-cost wide tunable vertical surface emitting laser over up to 40 km of standard single-mode fiber. The results confirm that converged fixed mobile WDM-PON systems based on low-cost lasers carrying discrete multitone modulation are a technically viable approach

Injection-Locked Single-Mode VCSEL for Orthogonal Multiplexing and Amplitude Noise Suppression

It has been shown earlier, that the injection locked semiconductor lasers enable effective amplitude noise suppression [1] and makes possible an extra level of signal multiplexing-orthogonal modulation [2], where DPSK and ASK NRZ channels propagate at the same wavelength [3]. In our work we use an injection-locked 1550 nm VCSEL as a slave laser providing separation of amplitude and phase modulations, carrying independent information flows. To validate the possibility of phase modulation extraction by an injection-locked VCSEL, an experimental setup shown in Fig. 1 has been built.Peer reviewe