All-optical reconfigurable non-inverted logic gates with a single semiconductor optical amplifier

Bingchen Han,Yi Liu

doi:10.1063/1.5061828

Abstract

All-optical reconfigurable non-inverted logic gates with a single semiconductor optical amplifier (SOA) is proposed. Compared with the probe light of continuous light, the clock (Clk) pulse sequences light is regarded as the probe light so that the output of logic gates is a non-inverted code which is suitable to the further combination of different logic gates. The scheme is based on a single SOA with four-wave mixing and cross-gain modulation. Multiple functional logic operations are implemented and switched by adjusting the center wavelength of tunable optical band-pass filter without altering the experimental device. In the experiment, all-optical multiple logic gates with 10 Gb/s return-to-zero of NOT, NOR, XNOR, AND, A¯•B and A•B¯ are realized. Meanwhile, because Clk probe light is a small signal, a saturable absorber (SA) is configured to improve the extinction ratio (ER) and optical signal to noise ratio (OSNR). For logic gates NOT, NOR and XNOR with Clk probe light, ER and OSNR are only deteriorated by 1 dB with the SA. For logic gate AND with Clk probe light, ER is improved by about 2 dB based on four-wave mixing and OSNR keep the original values with the SA respectively. For logic gates A¯•B and A•B¯ without Clk probe light, ER and OSNR are both only deteriorated by 0.5 dB. It has the potential to obtain more complex combinational logic gates.

Highlights

INTRODUCTIONBecause of avoiding optical/electrical/optical (O-E-O) conversion processes, all-optical signal processing (AOSP) can increase the system capacity and decrease the power consumption. Optical computing is one of the most difficult functions to be realized efficiently. Researchers have proposed a variety of all-optical logic gates to achieve optical computing, such as all-optical logic gate based on cross gain modulation (XGM) in cascaded single-end semiconductor optical amplifiers (SOA), XOR function based on SOAs based Mach–Zehnder interferometer (MZI), alloptical half-subtracter using the XGM effect of SOA, all optical NOR and OR gates implemented using SOA-based delay interferometer (SOA-DI), all-optical clocked flip-flops based on low-polarization-dependent SOA, all-optical XNOR gate and AND gate based on quantum dot (QD) SOAMZI and SOA-MZI respectively, logic AND Gate based on periodically polarized lithium niobate waveguide (PPLN), full-adder based on cascaded PPLN, all-optical switch based on pattern effect and cascaded second-order nonlinear effect of PPLN
For logic gate AND with Clk probe light, extinction ratio (ER) is improved by about 2 dB based on four-wave mixing and optical signal to noise ratio (OSNR) keep the original values with the saturable absorber (SA) respectively
Researchers have proposed a variety of all-optical logic gates to achieve optical computing, such as all-optical logic gate3 based on cross gain modulation (XGM) in cascaded single-end semiconductor optical amplifiers (SOA), XOR function based on SOAs based Mach–Zehnder interferometer (MZI),4–7 alloptical half-subtracter using the XGM effect of SOA,8 all optical NOR and OR gates implemented using SOA-based delay interferometer (SOA-DI)7,9,10, all-optical clocked flip-flops based on low-polarization-dependent SOA,11 all-optical XNOR gate and AND gate based on quantum dot (QD) SOAMZI and SOA-MZI respectively,10,12,13 logic AND Gate based on periodically polarized lithium niobate waveguide (PPLN),14 full-adder based on cascaded PPLN,15 all-optical switch based on pattern effect and cascaded second-order nonlinear effect of PPLN.16,17

Summary

INTRODUCTION

Because of avoiding optical/electrical/optical (O-E-O) conversion processes, all-optical signal processing (AOSP) can increase the system capacity and decrease the power consumption. Optical computing is one of the most difficult functions to be realized efficiently. Researchers have proposed a variety of all-optical logic gates to achieve optical computing, such as all-optical logic gate based on cross gain modulation (XGM) in cascaded single-end semiconductor optical amplifiers (SOA), XOR function based on SOAs based Mach–Zehnder interferometer (MZI), alloptical half-subtracter using the XGM effect of SOA, all optical NOR and OR gates implemented using SOA-based delay interferometer (SOA-DI), all-optical clocked flip-flops based on low-polarization-dependent SOA, all-optical XNOR gate and AND gate based on quantum dot (QD) SOAMZI and SOA-MZI respectively, logic AND Gate based on periodically polarized lithium niobate waveguide (PPLN), full-adder based on cascaded PPLN, all-optical switch based on pattern effect and cascaded second-order nonlinear effect of PPLN.. Using a single SOA to realize multifunctional reconfigurable logic gate can increase the flexibility and operability of logic devices with better extinction ratio (ER), and it is very promising to reduce the complexity of the system and the cost of the system with a few devices. These reports used the continual light as the probe light which induce some problem to limit the optical computing. It is necessary to do the logical NOT operation to get the non-inverted code signal This increases the complexity of the system and deteriorates the quality of signal. Because of “0” code noise and amplified noise of small signal “1” code of probe light respectively, a saturable absorber (SA) is configured to reduce deterioration

PRINCIPLE

EXPERIMENTAL RESULTS AND DISCUSSION

Result

CONCLUSION