CN109713458A

CN109713458A - A kind of silicon-based nano antenna with single radial characteristic

Info

Publication number: CN109713458A
Application number: CN201811474041.9A
Authority: CN
Inventors: 屈世伟; 曾元松
Original assignee: University of Electronic Science and Technology of China
Current assignee: University of Electronic Science and Technology of China
Priority date: 2018-12-04
Filing date: 2018-12-04
Publication date: 2019-05-03

Abstract

The invention discloses a kind of silicon-based nano antenna with single radial characteristic, belong to optical phased array, laser radar technique field, more particularly to a kind of silicon-based nano antenna array with single radial characteristic, in particular to high efficiency, high directionality silicon-based nano antenna array is suitable for laser imaging, in laser radar and optical communication system.Energy is coupled from silicon Medium Wave Guide using the aperture on metallic film, asymmetry is introduced using the strong resonance characteristic of nanometer paster antenna, to realize the one-way radiation of silicon substrate on-chip antenna, it is suppressed that the leakage to substrate side improves the efficiency of antenna.

Description

A kind of silicon-based nano antenna with single radial characteristic

Technical field

The invention belongs to optical phased array, laser radar technique field, and in particular to a kind of with single radial characteristic Silicon-based nano antenna array, in particular to high efficiency, high directionality silicon-based nano antenna array are suitable for laser imaging, laser radar In optical communication system.

Background technique

As laser imaging, the key technology of detection and ranging, optical phased array is in automatic Pilot, remote sensing mapping and army Thing field suffers from major application.Traditional optical phased array realizes beam scanning using mechanical system, due to mechanical system sheet The defects of body intrinsic low speed, have been unable to meet the requirement of modern high performance optical detection and ranging system.In recent years, added due to micro-nano The progress of work technique and the development of integrated optics technique, the on piece optical phased array technology based on optical waveguide array start to emerge in large numbers, Open the new direction of optical phased array.Compared to traditional optical phased array, on piece optical phased array can be big in nail cover Galvano scanning is realized on small area, overcomes the slow disadvantage of liquid crystal optical phased array response speed, and can pass through into Ripe chemical deposition technique is mass produced, thus scanning speed, integrated level and in terms of have it is congenital Huge advantage.

In numerous semiconductor integrated optics platforms, based on SOI (silicon on insulator, in insulating substrate Silicon) silicon chip on phased array have with CMOS (complementary metal-oxide semiconductor, metal oxygen Compound semiconductor) process compatible, can large-scale integrated, the features such as device size is small and low in energy consumption, be advantageously implemented high-speed and high-efficiency Automatically controlled scanning, thus be considered as the following high-performance optical radar system potential solution and become research hotspot.To silicon substrate The research of on piece phased array can trace back to 2007, and professor Gabriel in University of California, branch school, San Diego, which successfully has developed, to be worked as When most complicated silicon substrate phased array chip, device size is only 3.2mm x 2.6mm.2011, J.K.Doylend et al. benefit Two-dimentional light beam scanning is realized for the first time with the frequency scanning characteristic of SOI grid antenna.Equally it is based on SOI grid antenna, J.Sun et al. The extensive on piece phased array of 64 x 64 is reported for the first time, and correlative study Nature Journal is selected as the bright spot research of current year.

On a silicon substrate in the design of phased array, the design of antenna determine can effectively coupling luminous waveguide light, It is thus most important to entirely designing.But currently, silicon substrate on-chip antenna has all suffered from energy towards the leakage of substrate side, effect The low problem of rate.This is because the architectural characteristic of SOI itself (that is: fold by silicon substrate-silicon dioxide insulating layer-silicon device layer Layer structure) determined because light is invariably prone to propagate in the medium of high dielectric constant, and the silicon substrate of lower layer and The dielectric constant of silicon dioxide insulating layer is above free space, causes the radiation of the antenna positioned at silicon device layer to have very big by one Part can be revealed towards substrate-side, rather than be radiated in free space, this makes the energy dissipation of at least half.Simultaneously as The limitation of SOI technology, can not be directly in the lower section of device layer addition metallic reflection plate to realize one-way radiation.How not break In the case where bad soi structure characteristic, realizes the one-way radiation (not revealing towards substrate-side) of silicon substrate on-chip antenna, be to improve silicon The critical issue of base on-chip antenna efficiency and a problem.The present invention is exactly directed to this critical issue and proposes.

Summary of the invention

It is an object of the invention to: in view of the above-mentioned problems, providing a kind of nanometer patch array using slot-coupled with reality Now with the silicon substrate on-chip antenna of single radial characteristic.

Technical solution of the present invention is a kind of silicon-based nano antenna with single radial characteristic, which includes: silicon substrate Layer, silicon dioxide substrate layer, the waveguide of strip silicon, silica coating, metallic film, thin layer of silicon dioxide, nanometer patch battle array Column；The silicon dioxide substrate layer is located at silicon substrate layer upper surface, and the strip silicon waveguide is located at the upper of silicon dioxide substrate layer On the midline position on surface, the silica coating is covered on silicon dioxide substrate layer and strip silicon waveguide simultaneously, described Metallic film is located above silica coating, and the thin layer of silicon dioxide is located on metallic film；It is opened on the metallic film Equipped with nanometer array of orifices, the thin layer of silicon dioxide upper surface is provided with a nanometer patch array, one nanometer of aperture pair A nanometer patch is answered, and nanometer patch is located at the surface of corresponding nanometer aperture.

Further, the width of strip silicon waveguide and height are respectively 460nm and 240nm；The metallic film is that silver is thin Film, with a thickness of 80nm；Nanometer aperture on Ag films is square hole, and length and width is respectively 400nm and 100nm；Titanium dioxide Silicon thin layer with a thickness of 100nm；Nanometer patch is circular patch, radius 180nm.

The beneficial effects of the present invention are: coupling energy from silicon Medium Wave Guide using the aperture on metallic film, nanometer is utilized The strong resonance characteristic of paster antenna introduces asymmetry, to realize the one-way radiation of silicon substrate on-chip antenna, it is suppressed that substrate The leakage of side improves the efficiency of antenna.

Detailed description of the invention

Fig. 1 is nanometer patch array layered structure schematic diagram on the silicon chip based on slot-coupled described in embodiment 1.

Fig. 2 is the center section plan of nanometer patch array on the silicon chip based on slot-coupled described in embodiment 1.

Fig. 3 is nanometer patch array and traditional silicon substrate grid antenna on the silicon chip based on slot-coupled described in embodiment 1 In the antenna pattern of upper half-space and the lower half-space (substrate-side).

Fig. 4 is two-dimensional radiation directional diagram of traditional silicon substrate grid antenna in upper half-space and the lower half-space (substrate-side).

Fig. 5 is nanometer patch array and traditional silicon substrate grid antenna on the silicon chip based on slot-coupled described in embodiment 1 Gain pattern comparison.

Fig. 6 is beam scanning direction figure of the optical phased array under different inter-channel phase differences in embodiment 2.

Specific embodiment

In order to make the purpose of the present invention, the technical scheme and advantages are more clear, below with reference to implementing embodiment and attached drawing, Present invention is further described in detail.

1 nanometer of patch linear array design of embodiment

Nanometer patch array uses linear array form on the silicon chip based on slot-coupled of the present embodiment, as shown in Figure 1.Most The silicon layer 101 of bottom, silicon dioxide layer 102 together constitute typical soi structure with strip silicon waveguide 103, in silicon waveguide Layer is covered with silica coating 104.It is metallic film 105 on the upside of silica coating, is etched with array of orifices on metallic film 106.Top is nanometer patch array 108, has thin layer of silicon dioxide between nanometer patch array 108 and metallic film 105 106 supports.Fig. 2 show the center section plan of antenna in Fig. 1.The width and height of strip silicon waveguide 103 are respectively 460nm With 240nm.Ag films 105 with a thickness of 80nm, the length and width of the nanometer aperture 106 on Ag films 105 is respectively 400nm and 100 nm.Thin layer of silicon dioxide 106 with a thickness of 100nm, the radius positioned at the nanometer patch 108 of top is 180nm.It is fed by 106 pairs of nanometer patches 108 of aperture on Ag films.

This example design working frequency range is optic communication frequency range 1550nm.Array junctions composition is as shown in Figure 1, it uses linear array shape The spacing of formula, nanometer patch 108 and nanometer aperture is 850nm, number of unit 15.

Fig. 3 gives the two-dimentional normalized radiation pattern of the linear array in upper half-space and the lower half-space (substrate-side) of this example. As a comparison, Fig. 4 gives paper " Two-dimensional free-space beam steering with an The silicon substrate grid antenna used in optical phased array on silicon-on-insulator " is in upper half-space under Two-dimentional normalized radiation pattern of the half space (substrate-side) under same array bore.Silicon substrate grid antenna is phase on current silicon chip Control dominant form used by battle array.As can be seen that silicon substrate grid antenna is almost consistent in the radiation of the upper lower half-space, and by drawing Enter a nanometer patch array, antenna described in this example is effectively inhibited in the radiation of the lower half-space.Further, Fig. 5 The gain pattern for giving antenna described in this example and silicon substrate grid antenna compares, wherein 0 ° of direction corresponds to upward radiation (free space), the compromising emanation of 180 ° of directions counterpart substrate side.As can be seen that being deposited for silicon substrate grid antenna at 180 ° or so In the back lobe that one can compare with main lobe, front and back is than being 0.62dB.And for the antenna described in this example, front and back Than for 11.84dB.Simultaneously as the inhibition that substrate-side energy leakage obtains, the gain of antenna described in this example is also apparently higher than Silicon substrate grid antenna, to improve the efficiency of device.

2 nanometers of patch optical phased array designs of embodiment

Specifically, the linear array in embodiment 1 is extended perpendicular to feed direction, two-dimensional array is constituted.Pass through change The current feed phase of each linear array, may be implemented beam scanning.Its dimensional parameters is identical as example one, between channel and interchannel Away from being 0.9 μm.Fig. 6 gives beam scanning direction figure of the optical phased array in this example under different inter-channel phase differences. As can be seen that utilize proposed antenna, may be implemented ± 45 ° without graing lobe beam scanning.And in entire scanning range, All without apparent back lobe, show that the leakage of substrate-side is effectively inhibited.

Claims

1. a kind of silicon-based nano antenna with single radial characteristic, the antenna include: silicon substrate layer, silicon dioxide substrate layer, The waveguide of strip silicon, silica coating, metallic film, thin layer of silicon dioxide, nanometer patch array；The silicon dioxide substrate layer Positioned at silicon substrate layer upper surface, the strip silicon waveguide is located on the midline position of the upper surface of silicon dioxide substrate layer, described Silica coating is covered in simultaneously on silicon dioxide substrate layer and strip silicon waveguide, and the metallic film is covered positioned at silica Layer top, the thin layer of silicon dioxide are located on metallic film；Offer a nanometer array of orifices on the metallic film, described two Thin layer of silicon oxide upper surface is provided with a nanometer patch array, the corresponding nanometer patch of one nanometer of aperture, and nanometer is pasted Piece is located at the surface of corresponding nanometer aperture.

2. a kind of silicon-based nano antenna with single radial characteristic as described in claim 1, it is characterised in that strip silicon wave The width and height led are respectively 460nm and 240nm；The metallic film is Ag films, with a thickness of 80nm；Receiving on Ag films Meter little Kong is square hole, and length and width is respectively 400nm and 100nm；Thin layer of silicon dioxide with a thickness of 100nm；Nanometer patch Piece is circular patch, radius 180nm.