Intermediate infrared hyperbolic phonon polariton in-plane resonator and preparation and application thereof

Abstract

The invention relates to the technical field of micro-nano resonators, and particularly discloses a mid-infrared hyperbolic phonon polariton in-plane resonator and a preparation method and application thereof. The resonator takes alpha-MoO3 as a construction platform, and alpha-MoO3 can be coupled with mid-infrared electromagnetic waves to form hyperbolic phonon polaritons with high anisotropy and low optical loss. Alpha-MoO3 is accurately etched through a focused ion beam to form a hyperbolic reflection boundary, so that the propagation of hyperbolic phonon polaritons can be accurately controlled and resonated. The physical nature of negative reflection resonance is revealed by combining momentum space wave vector analysis and real space energy flux density characterization. Experiments show that through optimization of incident light frequency and cavity structure parameters, a mid-infrared light local light field is compressed to a full width at half maximum of only 0.291 [mu] m, and a light field compression factor up to 39 times is obtained.

Claims

1. A mid-infrared hyperbolic phonon polariton in-plane resonator, characterized in that: The mid-infrared hyperbolic phonon polaritons are composited by a micro-nano-processed silicon dioxide substrate and α-MoO3, wherein α-MoO3 is arranged on the upper surface of the silicon dioxide substrate, and the pattern obtained by micro-nano processing is a hyperbolic type, and the formula is as follows: , Among them, x and y are the horizontal and vertical coordinates of the boundary points of the hyperbolic cavity respectively; is the hyperbolic cavity angle; is the hyperbolic cavity gap; the hyperbolic cavity angle φ ranges from 45 to 70°, the hyperbolic cavity gap ranges from 0.8 to 1.6 μm, 0.4 μm < ∣x∣ <0.8μm, 0.4 μm < ∣y∣ <0.6 μm, and the α-MoO3 thickness is 50 to 200 nm.

2. The mid-infrared hyperbolic phonon polariton in-plane resonator according to claim 1, characterized in that: The mid-infrared hyperbolic phonon polariton in-plane resonator is produced by processing a hyperbolic reflection boundary on the surface of α-MoO3 by a focused ion beam etching method.

3. A method for preparing a mid-infrared hyperbolic phonon polariton in-plane resonator as claimed in claim 1, characterized in that: The following steps are involved: S1. Using a dual-temperature zone tube furnace to perform physical vapor deposition to prepare α-MoO3 single crystals; S2, peeling off the α-MoO3 single crystal by mechanical peeling method, placing the obtained single crystal on tape, then folding the tape in half several times and bonding it with an organic flexible substrate having adhesiveness to obtain a nanoscale α-MoO3 thin sheet; S3, cleaning the silicon dioxide substrate, and then transferring the α-MoO3 flakes to the silicon dioxide substrate, so that the adhesive flexible substrate of the α-MoO3 flakes is attached to the silicon dioxide substrate, and then fixed by heating; S4, cleaning the α-MoO3 nanosheets transferred to the silicon dioxide substrate obtained in S3 to remove the residual adhesive on the surface; and then using a high vacuum sputtering coating machine to deposit a carbon film on the surface of the α-MoO3 nanosheets; S5. Use focused ion beam etching to process and etch the α-MoO3 nanosheets deposited with the carbon film obtained in S4, and then anneal, repair and decarbonize the etched samples to obtain the mid-infrared hyperbolic phonon polariton in-plane resonator.

4. The preparation method according to claim 3, characterized in that: In step S1, the purity of the molybdenum trioxide powder used is not less than 99.9%.

5. The preparation method according to claim 4, characterized in that The parameters of the double-zone tubular furnace are set as follows: the temperature of the first zone is set to 750~800℃, the heating rate is 2~10℃ / min, the holding time is 5~10 h, and an argon-oxygen mixture with a ratio of 3:1~5:1 is used as the carrier gas. The temperature of the second zone is set to 650~700℃, the heating rate is 2~10℃ / min, the holding time is 5~10 h, and finally natural cooling is performed.

6. The preparation method according to claim 4, characterized in that In step S2, the tape is Ultronsystem blue film tape, the organic flexible substrate is polydimethylsiloxane, and the tape is folded 2 to 4 times.

7. The preparation method according to claim 4, characterized in that: In step S3, the heating temperature is 60-100°C, the heating rate is 2-10°C / min, and the heat preservation time is 5-15min.

8. The preparation method according to claim 4, characterized in that: In step S4, the high vacuum sputtering coating machine selects the Flash mode to perform 1 to 3 carbon film depositions.

9. The preparation method according to claim 4, characterized in that: In step S5, the processing current is 24~40pA, and the processing depth is 50~80% of the sample thickness; the annealing temperature is set to 300~400℃, the heating rate is 2~10℃ / min, and the holding time is 2~4 h; the atmosphere in the furnace is a mixed gas of argon and oxygen with a volume ratio of 3:1~5:

1.

10. Use of the mid-infrared phonon polariton in-plane resonator according to any one of claims 1 to 2 in the preparation of ultra-sensitive sensing and / or on-chip integrated optical circuit devices.

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