Tunable Vernier Series-Coupled Microring Resonator Filters Based on InGaAs/InAlAs Multiple Quantum-Well Waveguide

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors The article describes a tunable filter based on coupled racetrack resonators that are made of III-V materials. The tuning is achieved through changing the resonance wavelength for the coupled resonators. The dimensions of the resonators and the coupling coefficients are optimized to achieve the desired FSR of 9.4 nm also relying on the vernier effect. The article is well written with clear figures. The idea of using the vernier effect and tunable rings is not original. However, the modulating structure looks new and complex. The article shows experimental results which has a benefit for the reader. The experimental evidence of the validity of the idea is strong enough to convince me of the value of the work. Before publishing, the authors must address the following comments. Comments: 1- The sentence on line 17, "As the growing ...", needs language revision. 2- The study lacks a comparison with similar circuits to show its significance in terms of tuning range, voltage, speed and cost. Comments on the Quality of English Language

Minor corrections are required.

Author Response

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Reviewer 2 Report

Comments and Suggestions for Authors

The Comments are enclosed.

Comments for author File: Comments.pdf

Comments on the Quality of English Language

Minor editing of English language is required.

Author Response

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Author Response File: Author Response.docx

Reviewer 3 Report

Comments and Suggestions for Authors

The authors present an experimentally validated 4th order ring resonator filter which is tuned via the Vernier effect into resonance. The concept of the Vernier effect is well known in literature not only from the theoretical side but also has been proven and shown multiple times experimentally over the past 20 years, therefore additional information focussed on the real experiment is required before the paper is suitable for publication.

It is recommended to describe the electrical tuning mechanism and the experimental setup in more details including the instruments used and a picture of the setup used including the 4th order ring resonator with fiber coupling.

Author Response

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Round 2

Reviewer 3 Report

Comments and Suggestions for Authors

None