|
Reviewer 1
>Comments on Technical Content:
>
>This paper addresses a novel method to implement flat band slow light in asymmetric photonic crystal waveguide, which is the infiltration microfluidic in one side of the photonic crystal holes. However, some clarifications are required to allow the readers better understanding the paper contents. The main points are:
>1- Most of the waveguides are based on symmetric structure, why asymmetric structure is adopted here? An asymmetric waveguide structure will lead to a very low coupling efficiency when it is connected to a conventional strip waveguide. Since loss is also one of the biggest concerns in slow light research community, can you give some discussions about the coupling issue for the proposed waveguide?
>2- Because the one side holes are all modified, it makes a new photonic band structure. Thus, it is better to give the photonic band gap ranges for both the unchanged photonic crystals and the changed photonic crystals. You should make sure the guide modes for flat band slow light are all in the band gap.
>3- The paper reported that it focused on reducing the GVD, therefore, the GVD value of the waveguide should be given and compared with related works.
>4- “Even mode” and “the transverse electric-like (TE) mode” are used in the paper. It sounds like a 3D structure, so the vertical cross of the waveguide should be added in Fig. 1. Also, the structure parameters and the calculation parameters should be given.
>5- The paper only reported a plane wave expansion (PWE) method calculation results, either a FDTD simulation or an experiment of the design is preferred to prove the PWE analysis.
>6- Why the flat band appears in the structure, it should be given some comments.
>7- What’s the range of your optimizing fluid index and why did you chose this?
>8- What’s the range of your optimizing holes radius and why did you chose this?
>9- The relation of the optimizing parameters nf and R with Delay Bandwidth Product also with the Group Index should be plotted.
>10- Add reference for the plane wave expansion (PWE) method. |
|