All-Optical Three-Input “AND” Gate Dependent on a Differential Modulation Architecture

Round 1

Reviewer 1 Report

The manuscript entitled All-Optical Three-Input “AND” Gate Dependent on a Differential Modulation Architecture by Hassan Termos et al. proposed an all-optical three-input “AND” gate schemes with semiconductor optical amplifier Mach-Zehnder Interferometer (SOA-MZI). 

I recommend a minor revision of the manuscript for the authors to answer the following comments:

(1) In Fig.1, what’s the function of the phase shifter when performing “AND” operation? 

(2) For Fig.2, Fig. 5, and Fig. 9, what’s the physical meaning of the connection line between “BPF” and “PD”? Why does it have a different style compared with other signal lines? 

(3) I suggest authors to add more descriptions about the “VPI software” used for simulation. 

(4) In line 299, there is a typo. Please add “MZM” before “Mach-Zehnder modulator”.

(5) In Fig. 14, what’s the meaning of the figure underneath Fig. 14 (a)? 

Author Response

Kindly, find attached my response to your comments.

 

Author Response File: Author Response.pdf

Reviewer 2 Report

In this manuscript, the author proposed an all-optical "AND" gate scheme based on SOA-MZI and performed simulation and experimental studies on the proposed "AND" gate scheme. The author perform many simulated and experiemental studies on the performance of proposed architecture. However, the paper is not clearly presented and not well organized, which makes it very hard to understand.

(1)  This manuscript does not provide enough background. The author should explain in few words about how a SOA can be used to build a logic gate. What is the physics behind? What is the difference between SOA and SOA-MZI based approach?

(2)  The novelty of this manuscript is unclear. In line 40, it says "we proposed a novel scheme for a three-input logic ‘AND’ gate based on a SOA-MZI with a differential modulation mode in the electrical domain, and for the first time, using a 2 picosecond (ps) optical pulse sources (OPSs) at distinct repetition rates”. I don’t understand what is the novelty about “using 2ps pulse source for the first time”?

(3)  The author need to present the operation principle in a more clear way. Instead of just giving out the Boolean product Q=A*B*C (line 62), the author should try to explain in a little bit detail about what is the principle/physics behind. For example, it needs explain in general about how a SOA-MZI can be used to build a logic gate, and a “AND” gate.

(4)  Can the SOA generate any harmonic frequencies, i.e. n, m, p can be any integer? Is there difference in the amplitude of these harmonic components?

(5)  The author should use consistent description, either using frequency or wavelength in both figure 1 and context.

(6)  In line 87, how the author define the “ON” state? I don’t even know if the author use a NRZ PolSK signal.

(7)  Figure 1 makes people confused about what is SOA-MZI. It looks like SOA-MZI is one of the component…

(8)  How the author generate the normalized power in Figure 1? And it does have any caption about it.

(9)  In section 3, the author should describe briefly what is differential modulation architecture in a SOA-MZI. Usually in a MZM, a differential modulation scheme which means driving oppositely in both arms at the same time.

(10)                 Figure 1, figure 2 and figure 3 look too similar. The author can describe figure 1 in a different way and outline the difference between figure 2 and figure 3.

Author Response

Kindly, find attached my response to your comments.

Author Response File: Author Response.pdf

Reviewer 3 Report

The authors proposed an all-optical three-input AND gate through SOA-based MZI structure. The detail investigations including simulation and experiment have confirmed the AND function with very high operational speed. The concept is interesting and well-written. I suggest to accept the manuscript with minor revision:

1.      The SOA is hard to deal with the high-speed signal due to the limitation of the recovery time of carrier density. How it impacts on the performance of the proposed SOA-MZI when dealing with up to 200Gb/s data?

2.      Any optimization procedure applied to SOA to stimulate the proper XPM or XGM? Any input power or wavelength requirement?

Author Response

Kindly, find attached my response to your comments.

Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

it's much better