Preparation method of filling type sub-wavelength guide mode resonance optical filter

Abstract

The preparation method of the filled sub-wavelength guided mode resonant filter, firstly, the initial air-filled sub-wavelength grating is made on the quartz substrate by mask lithography and reactive ion beam etching, and then it is used as the substrate for coating and coating. Etching, which is characterized by: a) coating with physical vacuum deposition method, the material of the film is the material to be filled in the grating groove, and the thickness of the film is twice the depth of the subwavelength grating groove; b) etching the coating with reactive ion beam In the final sub-wavelength grating, the etched thickness of the material on the land of the grating is twice the depth of the groove of the sub-wavelength grating, and the thickness of the material etched on the groove of the grating is one time of the groove depth of the sub-wavelength grating. The present invention needs to fill the nanoscale grating grooves with materials whose thickness is accurate to the nanometer level, which is undoubtedly the most difficult to prepare in this type of optical filter. The invention combines the coating technology and the etching technology to provide a practical and feasible etching preparation method, which can conveniently prepare the filling type sub-wavelength guided mode resonant filter.

Description

technical field [0001] The patent of the present invention relates to the preparation method of the filled sub-wavelength guided mode resonant filter, and specifically relates to the etching technology of the grating structure and the vacuum coating technology. Background technique [0002] The phenomenon of subwavelength guided mode resonance has been studied earlier, but it is still a hot physical problem in recent years. This physical phenomenon can be used to make sub-wavelength guided mode resonant filters. Compared with traditional thin-film filters, this type of filter has the following advantages: (1) extremely narrow bandwidth, which can theoretically reach 0.01nm; ( 2) Extremely high reflection, which can reach 100% in theory; (3) Few layers, single layer or two to three layers; (4) Thin film layer thickness error is not strict. With its incomparable advantages, subwavelength guided mode resonant narrowband filters attract more and more scientific researchers to e...

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Problems solved by technology

However, there are still no mature products of this type at home and abroad. The main reason is that it is difficult to prepare the filter with the designed structure under the actual process conditions, especially for the filled subwavelength guided mode resonant filter. Filler, since the groove width of the grating is on the order of nanometers, it is extremely difficult to fill the groove with a certain thickness of material once the air-filled grating is etched. So far, no filled subwavelength guide has been seen. Mode Resonance Filter Fabrication Reported

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