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1

Highly-efficient three-port output by metal-mirror-based grating

Li H., Wang B., Shu W., Chen L., Lei L., Zhou J.

Optica Applicata

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2016

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Vol. 46, nr 1

87--92

EN

A highly-efficient three-port output of metal-mirror-based grating is proposed in this paper. The metal-mirror-based grating can function as a beam splitter which can diffract the normal incident wave into the 0th and the +/- 1st orders for both TE and TM polarizations with the usual duty cycle of 0.5. The analysis of the grating parameters can be optimized by rigorous coupled-wave analysis. The high efficiency for TE and TM polarizations shall be realized. By means of the numerical simulation, the depth and connecting layer thickness of grating can be accurately calculated. The efficiency of per port is near 33.3%, so the novel three-port output grating with a connecting layer would be an excellent optical element.

2

Three-port beam splitter based on a sandwiched grating with an improved aspect ratio

Shu W, Wang B, Li H, Li W, Chen L., Lei L., Zhou J.

Optica Applicata

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2015

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Vol. 45, nr 3

279--284

EN

In this paper, a fused-silica transmission grating used as a three-port beam splitter is designed by using the rigorous coupled-wave analysis, which is based on the sandwiched grating structure at the wavelength of 800 nm under normal incidence. Firstly, it is feasible to realize such a grating with the prescribed grating duty cycle and grating period. Next, high efficiency can be also achieved for both TE and TM polarizations. Moreover, the aspect ratio of the grating depth to the ridge width can be improved, which is significant for practical applications. At last, the three-port beam splitter is designed with a covering layer on the surface, which can extend its life service.

3

Polarization-independent metal-dielectric grating with improved bandwidth

Wang B, Li H, Shu W, Li W, Li C, Lei L, Zhou J

Optica Applicata

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2015

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Vol. 45, nr 1

71--77

EN

A polarization-independent reflective grating with improved bandwidth is presented based on the mixed metal-dielectric grating. The novel grating is composed of the substrate, the metal slab, two dielectric layers, and the covering layer. The grating parameters are optimized for the special duty cycle of 0.6 at an incident wavelength of 1550 nm used in dense wavelength division multiplexing (DWDM). With the designed grating, high efficiency can be diffracted into the reflective –1st order for both TE and TM polarizations, where the polarization-independence is exhibited. Most importantly, the efficiency of more than 90% can be achieved within the incident wavelength bandwidth of 1262–1686 nm, where the bandwidth is improved greatly compared with the reported surface-relief single-layer grating. The reflective grating can have advantages of high efficiency, polarization-independence, and wide bandwidth, which should be useful for DWDM applications.