Silicon-on-Insulator Optical Buffer Based on Magneto-Optical 1 × 3 Micro-Rings Array Coupled Sagnac Ring

Round 1

Reviewer 1 Report

Dear Editor,

the manuscript under review entitled "Silicon-on-insulator optical buffer based on magneto-optical 1×3 micro-rings array coupled Sagnac ring" reports on a theoretical study of an optical buffer formed by coupled ring resonators.

In general, the work is reasonably structured and organized. The manuscript reads well. Provided figures are clear, although the quality could be improved. The theoretical analysis is presneted in an appropriate way. The study is supported by mathematical model. Results presentation and overall discussion is solid.

My comments to this work are provided below.

(1) Please benchmark your study with the available state-of-the-art results.

(2) Can Authors comment on the coupling losses as well as on the overall losses of the proposed/investigated optical buffer.

(3) What are the main limitations/shortcommings of he presented approach in respect to the buffering time.

(4) Can Authors comment on the system stability in terms of temperature variations? 

(5) It is well known that 1 nm difference in the ring resonator geometry can incude 1 nm shift in the resonance. tolerance analysis or study should be included as well.

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Reviewer 2 Report

In the present paper, the authors study a switchable optical buffer using the nonreciprocal silicon-on-insulator (SOI) magneto-optical micro-ring (MOMR) array coupled with the Sagnac ring. The subject of the paper considered is not noteworthy.

There are a number of practical issues that would need to be addressed if the manuscript were resubmitted.

1. In the introduction of the manuscript, the authors mentioned that the optical buffers can be divided into two categories: buffers using slow light effects and buffers based on optical structures. In fact, slotted photonic crystal waveguides and photonic crystal cavities with ultra-high Q-factors and ultra-small mode volumes can be also used for the design of the optical buffers (Kassa-Baghdouche, L., & Cassan, E. (2018). Photonics and Nanostructures-Fundamentals and Applications, 28, 32-36, Kassa-Baghdouche L, Boumaza T and Bouchemat M 2015 Physica Scripta 90 065504). These references should be included in the manuscript. Moreover, the ability of these structures for the design of the optical buffers should be discussed in the main manuscript.
2. In the subsection (Sagnac Ring with 1×3 MOMRs), the authors illustrate in figure 1(b) the section diagram of the micro-ring array in a three-layer non-reciprocal MO waveguide structure. Such structure consists of one dielectric layer (silicon) and two MO layers (Ce:YIG and SGGG). Why did the authors choose these values of the geometrical parameters?
3. For the construction and principles of the proposed optical buffer, the authors should explain why Sagnac Ring and the MOMR array structure are chosen?
4. In the third section (Results and discussions), it is better to have a table when making a comparison with some other similar optical buffers devices.
5. As mentioned in subsection 3.3 (Read-out operation of the optical buffer), When the optical signal is stored in the optical buffer for a period of time, the PCM is transformed into an amorphous state. Please add the necessary descriptions of the amorphous state.
6. Since this is a numerical simulation manuscript, it would be nice if the authors present more results. Right now they just focus on transmission spectra. Could they perhaps provide some kind of a more general prediction for how the effective buffer time depends on the geometrical parameters of the proposed optical buffer? The signal evolution, effective buffer time, and readout operation in the buffer should be investigated and compared with those proposed in the literature.

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Reviewer 3 Report

Comments for author File: Comments.pdf

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

No further comments to this work

Reviewer 2 Report

The authors have implemented my suggestions.