Fig. 1. Experimental setup of a VCSEL neuron for reproducing the pyramidal neuron-like dynamics dominated by dCaAPs. AWG, arbitrary waveform generator; DFB, distributed feedback laser; OI, optical isolator; VOA, variable optical attenuator; PC1 and PC2, polarization controllers; Mod, Mach–Zehnder modulator; OC1 and OC2, optical couplers; CIRC, circulator; Bias & T Controller, bias and temperature controller; PD, photodetector; PM, power meter; SCOPE, oscilloscope; OSA, optical spectrum analyzer.

Fig. 2. (a) Polarization-resolved mode powers as functions of applied bias current with a constant temperature of 18.42°C. (b) Optical spectrum of free-running VCSEL with a bias current of 5.4 mA.

Fig. 3. Experimental results for the pyramidal neuron-like dynamics dominated by dCaAPs. (a) Inputs of the VCSEL neuron. (b) Outputs of the VCSEL neuron [also pyramidal neuron-like dynamics dominated by dCaAPs under the optical injection in (a)].

Fig. 4. Experimental results for the temporal map of superimposed consecutive outputs from VCSEL neuron. Red dashed box labels the damped oscillations of the VCSEL.

Fig. 5. Experimental setup of a VCSEL neuron for XOR classification task based on the dynamics above. Mod1, Mod2, Mach-Zehnder modulators; VODL, variable optical delay line; PC3, polarization controller.

Fig. 6. Experimental results of XOR classification tested by eight two-bit binary cases. (a1)–(c2) Eight two-bit binary cases. (a3)–(c3) Inputs of the VCSEL neuron. (a4)–(c4) Outputs of the VCSEL neuron for the results of XOR classification. (a1)–(a4) DT=2  ns. (b1)–(b4) DT=5  ns. (c1)–(c4) DT=10  ns.

Fig. 7. Simulated results of the pyramidal neuron-like dynamics dominated by dCaAPs in the VCSEL under optical injection. (a) Inputs of the VCSEL neuron. (b) The responses of the VCSEL neuron with the inputs of (a).

Fig. 8. Bifurcation diagrams of the maximum IX as functions of K with different currents. (a)–(c) Corresponding to μ=2.3, 2.5, and 2.6.

Fig. 9. Spiking dynamics of VCSEL under the dropped pulses with different duration times. (a) Inputs of the VCSEL. (b) Outputs of the VCSEL under the inputs of (a).

Fig. 10. All-optical XOR classification tested numerically by 10 two-bit binary cases. (a1)–(c2) 10 two-bit binary cases. (a3)–(c3) The outputs of the VCSEL neuron for the results of XOR operation. (a1)–(a3) DT=0.83  ns. (b1)–(b3) DT=3  ns. (c1)–(c3) DT=6  ns.