Method for realizing intrinsic optical bistability based on light-induced blackbody effect and application thereof

Abstract

The application discloses a method for realizing intrinsic optical bistability based on a light-induced blackbody effect and application thereof, and belongs to the technical field of optics, specifically, two lasers are selected as excitation light to excite a light-induced blackbody absorption material; the method causes the material to generate the light-induced blackbody effect through laser irradiation; when the power density of the irradiation laser reaches or exceeds a threshold value at which the light-induced blackbody effect occurs, the optical absorption and light emission of the material increase sharply in a wide waveband (200nm-2500nm) range, and the characteristics of photon avalanche absorption and light emission are presented. In the case of double-beam laser irradiation, the power of the two lasers is appropriately selected, and intrinsic optical bistable light emission and bistable scattering can be constructed.

Description

Technical Field

[0001] This invention belongs to the field of optical technology, specifically relating to a method for achieving intrinsic optical bistable states based on the photoinduced blackbody effect and its applications. Background Technology

[0002] Optical bistableness is a crucial phenomenon in nonlinear optics. Devices based on the principle of optical bistableness are fundamental components for optical switching, optical storage, and optical logic operations, with broad applications in optical communication and all-optical computer development. The study of optical bistableness in rare-earth materials is a relatively new research area. It utilizes the multiphoton upconversion emission characteristics of rare-earth ions to achieve optical bistableness without a resonant cavity, hence it is also called intrinsic optical bistableness (IOB). Intrinsic optical bistableness without an optical resonant cavity offers a new approach to achieving high integration of all-optical logic devices.

[0003] Many promising applications rely on optical bistableness and optical switches based on optical bistableness. Examples include all-optical logic devices, quantum computers, optical data storage, and all-optical communication control. Before the discovery of intrinsic optical bistableness, an optical feedback cavity was required to achieve optical bistableness. As early as 1979, Bowden and Sung theoretically addressed the intrinsic bistableness problem in condensed matter media for the first time. In 1994, Hehlen and Güdel first observed and reported intrinsic bistableness based on lanthanides Yb 3+ Intrinsic bistable luminescence of ions. They are present in Cs3Y2Br9:10% Yb 3+ Experiments were conducted on the crystal to monitor the coupling of Yb 3+ Cooperative luminescence of ion pairs. Subsequently, in Yb 3+ 1% Yb ion-doped bromide crystals 3+ :CsCdBr3,10% Yb 3+ (Cs3Lu2Br9 and Cs3Yb2Br9), Yb 3+ -and Tm 3+ - Co-doped silicate glass, Yb 3+ -and Er 3+ Co-doped CsCdBr3 crystal, Yb 3+ Doped oxide crystals, Yb 3+ Intrinsic optical bistability and photo-switching phenomena with cooperative luminescence have been observed in doped LiNbO3:MgO crystals and Cr-doped fluorinated calcium lithium crystals. An increasing number of papers aim to provide a reasonable explanation for intrinsic optical bistability from a theoretical or mechanistic perspective. Summarizing these experimental and theoretical works, the proposed mechanisms are (a) Lorentz local field correction by polarization population coupling, and (b) Yb 3+ Temperature-dependent absorption in ion-doped systems, (c)Tm 3+ -and Yb3+ - Avalanche population and energy transfer in co-doped glasses, (d) Thermally induced luminescence quenching in Cr ion-doped crystals, (e) Yb 3+ The electronic degrees of freedom of the ion and [YbBr6] 3- Coordination unit A 1g Coupling between local vibrational modes. Two main theoretical approaches have been used to address the intrinsic optical bistable phenomenon. One is the density matrix method, which is based on a quantum mechanical description of the dynamics of the system under the influence of reversible internal and external interactions. Using this method, and considering appropriate relaxation terms, it is theoretically possible to... 3+ Intrinsic optical bistableness can be reproduced in doped systems. Another method is the rate equation method based on the population of energy states, which, by considering the migration rate of the system, can relate the population change rates of different energy levels.

[0004] Rate equations are very convenient for handling the residence and de-residence of excited states caused by energy transfer between rare earth ions and various phonon-assisted physical processes. Similarly, using rate equation methods, researchers have theoretically reproduced and predicted the residence and de-residence of Yb. 3+ Doped systems, Yb 3+ -And Ho 3+ - Co-doped systems and Yb 3+ -and Tm 3+ - Intrinsic optical bistability in co-doped systems. However, these explanations and formalistic descriptions do not provide a real and robust microscopic physical mechanism, especially for Tm occurring at room temperature. 3+ The intrinsic optical bistable nature of light emission has potential applications in all-optical devices. In 2004, Auzel in Yb 3+ The intrinsic optical bistability and thermal avalanche of rare-earth ions for RE-RE energy transfer were obtained in the excited state. However, it should be noted that in Yb 3+ Intrinsic optical bistability can only be observed in doped crystals at low temperatures (<35K), but in Yb 3+ -and Tm 3+ Intrinsic optical bistability can be obtained at room temperature in co-doped glasses.

[0005] The intrinsic optical bistability of rare-earth ion-doped crystals has enormous potential application value in all-optical devices, thus attracting great attention from researchers. In 2004, the renowned physicist Auzel also studied and explained the intrinsic optical bistability of rare-earth ions in *Chemical Reviews*, suggesting that the intrinsic optical bistability originates from energy transfer between rare-earth ions and Yb 3+ Thermal avalanche process in ion-excited states. However, it is noteworthy that in mono-doped Yb... 3+ Intrinsic optical bistability in crystals can only be observed at low temperatures (<35K), but in Yb 3+ -Tm3+ Intrinsic optical bistability in co-doped systems can occur at room temperature. To date, no reasonable and convincing theoretical explanation has been provided for this discrepancy. Furthermore, all published studies have observed intrinsic optical bistability in bulk macroscopic materials, and the frequency upconversion processes involved are all two-photon or three-photon processes. Currently, the conditions for achieving intrinsic optical bistability based on lanthanide ion ff transitions are quite demanding, such as the need for observation at low temperatures (<35K), weak fluorescence making measurement difficult, and the requirement for very high chemical purity in the materials. For these reasons, international research on rare-earth intrinsic optical bistability is currently limited to material discovery and mechanism exploration, with research on device applications proving difficult to conduct. Summary of the Invention

[0006] To address the limitations of existing technologies, such as stringent conditions for achieving intrinsic optical bistable states (observable only at low temperatures <35K), weak fluorescence making measurement difficult, and the requirement for high chemical purity in materials, this invention provides a method for achieving intrinsic optical bistable states based on the photoinduced blackbody effect and its applications. This method induces a photoinduced blackbody effect in the material through laser irradiation. When the power density of the irradiating laser reaches or exceeds the threshold for the photoinduced blackbody effect, the material's optical absorption and emission increase dramatically over a wide wavelength range (200nm–2500nm), exhibiting characteristics of photon avalanche absorption and emission. Under dual-beam laser irradiation, by appropriately selecting the power of the two laser beams, intrinsic optical bistable emission and bistable scattering can be constructed.

[0007] This invention is achieved through the following technical solution:

[0008] A method for achieving intrinsic optical bistability based on the light-induced blackbody effect includes the following:

[0009] Two laser beams were selected as excitation light to excite the light-induced blackbody absorbing material;

[0010] The selection principles for the two laser light sources are as follows:

[0011] The first laser beam has a higher power and an arbitrary wavelength; the second laser beam has a lower power and its wavelength is consistent with the characteristic absorption wavelength of the light-induced blackbody absorbing material. The light-induced blackbody effect can be produced when the two laser beams irradiate the light-induced blackbody absorbing material at the same time, but the light-induced blackbody effect will not be produced when either of the laser beams irradiates the light-induced blackbody absorbing material alone.

[0012] Furthermore, the light-induced blackbody absorbing material can produce light absorption of not less than 0.1% for the second laser beam.

[0013] Furthermore, if the light-induced blackbody absorbing material contains Yb3+ The second laser source has a wavelength of -980nm; if the light-induced blackbody absorbing material contains Er... 3+ The second laser source has a wavelength of -1530 nm; if the light-induced blackbody absorbing material contains Nd... 3+ The wavelength of the second laser source is -1064nm; if the photoinduced blackbody absorbing material contains CdSe quantum dots, the wavelength of the second laser source is 400-600nm depending on the size of the quantum dots; and so on, so that the light absorption coefficient of the material is greater than 90% in a wide wavelength range when the photoinduced blackbody effect occurs.

[0014] Furthermore, the wideband is 200nm to 2500nm.

[0015] Furthermore, the photoinduced blackbody absorbing material includes oxides, fluorides, MREF4, mixed nanostructures, or carbon-based materials; wherein M is Li, Na, K, or Ba; the oxides include Y2O3, La2O3, Lu2O3, Gd2O3, Yb2O3, ZrO2, and Y3Al5O3. 12 Ca 12 Al 14 O 33 Y2Si2O7, Y4Zr3O 12 YVO4, Sr2CeO4, Gd3Ga5O 12 Yb3Al5O 12 NdAlO3, PrO2 or BaCuSi4O 10 The fluorides include YF3, LaF3, LuF3, GaF3, or YbF3; the MREF4 includes NaYF4, LiLaF4, BaLuF4, or KGdF4; the mixed nanostructures include Ag-SiO2-Er2O3, Yb2O3 / Au, Nd2O3 / Au, or Gd2O3 / Au; and the carbon-based materials include graphene, carbon nanotubes, or monolayer graphene.

[0016] Furthermore, the method specifically includes the following steps:

[0017] Step 1: Preparation of photo-induced blackbody material thin films;

[0018] Place 5 mmol of Y2O3 powder into a tablet mold with a diameter of 12 mm, press it to 8t using a BJ-15 flat tablet press, maintain the pressure for 20 seconds, release the pressure, and remove the tablet sample.

[0019] Step 2: Simultaneously irradiate the inducing material with two laser beams to induce a photoinduced blackbody effect;

[0020] A 20W 980nm laser beam is focused onto a Y₂O₃ thin film, and another 5W 980nm laser beam is focused on the same point. When only the 20W 980nm laser is on, the thin film sample does not emit light. When the 5W 980nm laser is turned on, the Y₂O₃ thin film enters the state of photoinduced blackbody absorption and blackbody radiation. At this time, the 5W 980nm laser is turned off, leaving only the 20W 980nm laser beam to irradiate the sample, and the Y₂O₃ thin film sample remains in the state of photoinduced blackbody radiation. If the 20W 980nm laser is briefly blocked for less than 1 second, the Y₂O₃ thin film sample instantly exits the state of photoinduced blackbody radiation and enters a non-emitting state.

[0021] On the other hand, the present invention also provides an application of the method for realizing intrinsic optical bistable states based on the photoinduced blackbody effect in the construction of optical bistable devices, specifically including the following:

[0022] The optically bistable device based on the optically induced blackbody effect consists of an optically induced blackbody material, two laser light sources, and two photodetectors. The two laser beams illuminate the same point on the optically induced blackbody material, and the two photodetectors collect the emitted and scattered laser light from the material, respectively. The photodetector that collects the scattered laser light is configured in a mirror image with the excitation light source.

[0023] Furthermore, the optical bistable device can be constructed into a multi-level optical integrated device through series and parallel connections.

[0024] Compared with the prior art, the advantages of the present invention are as follows:

[0025] 1. A wide range of materials can be selected, and there are no strict requirements on the purity of the materials. Many types of materials can generate new energy states by using the light-induced blackbody effect, thereby causing a dramatic enhancement of light absorption and light radiation, and further generating intrinsic optical bistability.

[0026] 2. It does not depend on the wavelength of the excitation light. Theoretically, light of any wavelength can be used as excitation light to induce a photo-induced blackbody effect in the material, thereby producing an intrinsic optical bistability in the material.

[0027] 3. Intrinsic optical bistableness based on the light-induced blackbody effect manifests in two ways: luminous intensity bistableness and scattered laser intensity bistableness. Therefore, bistable data can be obtained by detecting either the luminous intensity or the scattered light intensity.

[0028] 4. The intensity of light radiation generated by the light-induced blackbody effect and the intensity of light scattered by the material are much greater than the light emission intensity of the ff transition. Therefore, intrinsic optical bistable measurement based on the light-induced blackbody effect is easier and does not require low temperature conditions.

[0029] 5. The optical absorption enhancement of materials caused by photo-induced absorption is an enhancement in a wide wavelength range (200nm~2500nm). The material after photo-induced absorption has obvious absorption of electromagnetic waves in a wide wavelength range (200nm~2500nm), so there is no limitation on the wavelength of the first laser beam.

[0030] 6. Similar to other intrinsic optical bistable systems, it can be achieved without an optical resonant cavity. Attached Figure Description

[0031] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the accompanying drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn to scale.

[0032] Figure 1 : Schematic diagram of light-induced blackbody absorption and strong light absorption phenomenon generated by the material; a: Changes in the intensity of light emission (left) and scattering of 980nm excitation light (right) of Yb2O3 material before and after light-induced blackbody absorption; b: Schematic diagram of photon avalanche upconversion luminescence principle; c: Changes in scattering intensity (curve 1) of six irradiation lasers at 266nm, 405nm, 532nm, 650nm, 808nm and 1560nm before and after the appearance of light-induced blackbody effect (curve 2); d: Under the light-induced blackbody absorption state, the relative absorption (absorption ratio) of the sample to the six probe lasers is all above 90%, showing strong light absorption characteristics;

[0033] Figure 2 Intrinsic optical bistableness based on the photoinduced blackbody effect. a, Photoinduced blackbody luminescence of Y₂O₃ powder exhibits obvious photon avalanche and optically bistable luminescence characteristics. The occurrence of photoinduced blackbody radiation coincides with the sudden decrease in the intensity of the scattered irradiated laser light, and the scattered laser light intensity also exhibits bistable characteristics. b, 0.7 mol% Yb 3+ The doping of Y2O3 powder increases the initial absorption of 980nm laser, reduces the threshold power for the photoinduced blackbody effect, and results in a smaller bistable ring.

[0034] Figure 3 : Photoinduced blackbody radiation spectrum. Under irradiation with 980nm lasers of different powers, the photoinduced blackbody radiation spectrum of Y₂O₃ basically conforms to the fitting curve of Planck's law. After the photoinduced blackbody effect occurs, the material converts the laser light irradiating it into broadband electromagnetic radiation, and the spectrum of the material's radiation is very similar to that of blackbody radiation (or thermal radiation);

[0035] Figure 4: Schematic diagram of the spectrum and integrated intensity of photoinduced blackbody absorption; a: Emission spectrum of Y2O3 material under different 980nm excitation light powers (0-30W); b: Changes in the integrated intensity (top) and scattering intensity (bottom) of photoinduced blackbody emission (400-800nm) of Y2O3 material as the 980nm excitation light power increases. During the process of increasing the pump power from 0W to 22W, the sample does not emit light. As the pump power continues to increase to 22W, the sample instantly enters the photoinduced blackbody effect state, emitting broad-spectrum incandescent light (a). At this time, the slope n = logI / logP instantly increases to 70.5 (b top), and the scattered laser intensity instantly decreases (b bottom), exhibiting the characteristics of avalanche emission and avalanche absorption. Where I is the integrated intensity of the photoinduced blackbody radiation light, and P is the laser power;

[0036] Figure 5 : A diagram illustrating the photonic avalanche luminescence and intrinsic bistable luminescence mechanism based on the photoinduced blackbody effect. When the laser power density exceeds a certain threshold, a new energy state is generated within the material. This new energy state gives the material strong light absorption capabilities and exhibits broadband strong absorption characteristics. The new energy state is photoinduced under laser irradiation; it disappears rapidly after the irradiating laser is removed. Whether a new energy state is generated in the material when irradiated by a laser is the physical basis for the formation of intrinsic optical bistableness.

[0037] Figure 6 Two laser beams were used to irradiate a Yb₂O₃ powder sample to achieve intrinsic optical bistableness. The excitation light was a 5W 808nm continuous laser, and the induction laser was a 980nm pulsed laser (average power 10W, repetition rate 10Hz, pulse width 40ms). Both laser beams were focused on the same point on the sample. When only the 5W 808nm laser was used, the sample did not exhibit a photoinduced blackbody effect and remained in a dark, non-emitting state. When the 980nm pulsed laser was simultaneously activated, the sample exhibited new optical absorption at 808nm, and the scattered light intensity decreased slightly. After approximately 10 seconds, the sample entered a photoinduced blackbody state, with a sudden increase in luminescence and a sudden decrease in scattering at 808nm. At this point, removing the 980nm pulsed laser resulted in the sample remaining stably in a photoinduced blackbody radiation state (bright state), meaning that excitation by a single 5W 808nm laser could maintain the sample in a bright state. When the 808nm laser is momentarily blocked, the photo-blackbody effect immediately disappears, and the sample returns to a non-emitting dark state under 5W 808nm laser irradiation. Detailed Implementation

[0038] To clearly and completely describe the technical solution and its specific working process of the present invention, the specific embodiments of the present invention are as follows, in conjunction with the accompanying drawings:

[0039] Example 1

[0040] A method for achieving intrinsic optical bistability based on the light-induced blackbody effect includes the following:

[0041] Under intense 980nm laser irradiation, Y₂O₃ powder emits bright white light, while simultaneously exhibiting blackbody absorption characteristics. That is, while emitting broadband electromagnetic waves, the material exhibits significant and strong absorption of electromagnetic waves across a wide wavelength range (200nm–2500nm). The sudden generation of broadband luminescence and the rapid increase in light absorption occur synchronously after a significant energy accumulation process. These characteristics are similar to photon avalanche luminescence, as shown in the attached figure. Figure 1 As shown in Figure a. Reported avalanche upconversion luminescence generally satisfies the following conditions, as shown in the attached figure. Figure 1 As shown in b: weak E0 ground-state absorption, strong E1 excited-state absorption, and effective cross-relaxation between the two transitions from the high-energy level E2 to the excited-state level E1 and from the ground-state level E0 to the excited-state level E1, gradually populating the excited-state level E1. When the population of the excited-state level E1 reaches a certain level, the excited-state absorption of E1 and the cross-relaxation of E0→E1+E2→E1 increase rapidly, causing the radiative transitions from the high-energy level E2 above to increase sharply in an avalanche manner. Obviously, the enhancement of excited-state absorption and the increase of excited-state population constitute a positive feedback process, manifested as a sudden enhancement of excited-state absorption and upconversion luminescence. However, in this embodiment, the Y2O3 powder material exhibits different avalanche luminescence characteristics under laser irradiation: avalanche-like luminescence enhancement is accompanied by avalanche-like light absorption enhancement (see attached diagram). Figure 1 (c) and exhibits broad-band blackbody emission and blackbody absorption characteristics (see appendix) Figure 1 (d); more importantly, the luminescence process exhibits optically bistability (see appendix). Figure 2 a) When light-induced blackbody absorption occurs, the material used in the experiment will strongly absorb the irradiated light. Regardless of the wavelength of the irradiating laser, the irradiated material exhibits strong light absorption across the entire spectrum (see appendix). Figure 1 d). These two characteristics definitively indicate that these energy levels with broadband strong absorption are newly generated quantum states, photoinduced by strong light irradiation, and possess strong light absorption across the entire spectrum. More precisely, after this novel photon avalanche optical frequency conversion, the material converts the light incident upon it into broadband electromagnetic radiation, the spectrum of which is very similar to blackbody radiation (or thermal radiation), as shown in the attached figure. Figure 3 As shown in the attached figure. Meanwhile, the material exhibits significant and strong absorption (greater than 90%) of electromagnetic waves across a wide wavelength range (200nm–2500nm), as shown in the attached figure. Figure 1 As shown in d. This new phenomenon is called the photoinduced blackbody effect or photoinduced blackbody effect.

[0042] This embodiment demonstrates that:

[0043] (1) Based on the light-induced blackbody effect, intrinsic optical bistable does not require an optical resonant cavity and belongs to intrinsic optical bistable.

[0044] (2) When the light-induced blackbody effect occurs, the material’s absorption of light is no longer selective, that is, light or laser of any wavelength will be strongly absorbed by the material.

[0045] (3) If the initial light absorption of the material is large (usually not less than 1%), the light-induced blackbody effect will occur. The larger the initial light absorption coefficient, the easier it is for the light-induced blackbody absorption phenomenon to occur.

[0046] (4) A novel intrinsic optical bistable state can be achieved by utilizing the photoinduced blackbody effect. The intrinsic optical bistable emission based on the photoinduced blackbody effect not only exhibits upconversion emission but also downconversion emission, that is, it emits white light across the entire spectrum. Its intrinsic optical bistable characteristics will still be reflected in the intensity of the scattered light from the irradiated laser.

[0047] (5) Under strong light irradiation, various materials exhibit strong optical absorption and optically bistable luminescence characteristics similar to blackbodies. Compared with intrinsic optical bistable luminescence based on lanthanide ion ff transitions, intrinsic optically bistable luminescence based on the photoinduced blackbody effect has a very wide range of selectable materials and very low requirements for material preparation.

[0048] Example 2

[0049] A method for achieving intrinsic optical bistability based on the light-induced blackbody effect includes the following:

[0050] Two laser beams were selected as excitation light to excite the light-induced blackbody absorbing material;

[0051] The selection principles for the two laser light sources are as follows:

[0052] The first laser beam has a higher power and an arbitrary wavelength; the second laser beam has a lower power and its wavelength is consistent with the characteristic absorption wavelength of the light-induced blackbody absorbing material. The light-induced blackbody effect can be produced when the two laser beams irradiate the light-induced blackbody absorbing material at the same time, but the light-induced blackbody effect will not be produced when either of the laser beams irradiates the light-induced blackbody absorbing material alone.

[0053] The light-induced blackbody absorbing material can produce light absorption of not less than 0.1% for the second laser beam.

[0054] If the light-induced blackbody absorbing material contains Yb 3+ The second laser source has a wavelength of -980nm; if the light-induced blackbody absorbing material contains Er... 3+The second laser source has a wavelength of -1530 nm; if the light-induced blackbody absorbing material contains Nd... 3+ The wavelength of the second laser source is -1064nm; if the photoinduced blackbody absorbing material contains CdSe quantum dots, the wavelength of the second laser source is 400-600nm depending on the size of the quantum dots; and so on, so that the light absorption coefficient of the material is greater than 90% in a wide wavelength range when the photoinduced blackbody effect occurs.

[0055] The wideband is 200nm to 2500nm.

[0056] The light-induced blackbody absorbing material includes oxides, fluorides, MREF4, mixed nanostructures, or carbon-based materials; wherein M is Li, Na, K, or Ba; the oxides include Y2O3, La2O3, Lu2O3, Gd2O3, Yb2O3, ZrO2, and Y3Al5O3. 12 Ca 12 Al 14 O 33 Y2Si2O7, Y4Zr3O 12 YVO4, Sr2CeO4, Gd3Ga5O 12 Yb3Al5O 12 NdAlO3, PrO2 or BaCuSi4O 10 The fluorides include YF3, LaF3, LuF3, GaF3, or YbF3; the MREF4 includes NaYF4, LiLaF4, BaLuF4, or KGdF4; the mixed nanostructures include Ag-SiO2-Er2O3, Yb2O3 / Au, Nd2O3 / Au, or Gd2O3 / Au; and the carbon-based materials include graphene, carbon nanotubes, or monolayer graphene.

[0057] Example 3

[0058] This embodiment provides a method for achieving intrinsic optical bistability based on the light-induced blackbody effect, specifically including the following steps:

[0059] Step 1: Preparation of Y2O3 material thin films;

[0060] All chemicals were of analytical grade and required no further purification before use; yttrium oxide (Y₂O₃, 99.99%) was supplied by Shanghai Aladdin Reagent Co., Ltd.

[0061] Place 5 mmol of yttrium oxide powder into a 12 mm diameter tablet mold, pressurize to 8 t using a BJ-15 flatbed tablet press (Tianjin, China), maintain the pressure for 20 s, release the pressure, and remove the tablet (approximately 2 mm thick).

[0062] Step 2: Irradiate the Y₂O₃ thin film with a 980nm continuous laser with adjustable power from 0 to 30W, and focus the laser spot to ~1mm. 2 By gradually adjusting the laser power to 22W, the size of the material is determined, inducing a photo-induced blackbody effect, such as... Figure 1 As shown in Figure a, the emitted and scattered laser light from the sample is collected using optical fibers or lens arrays, and the collected light signals are fed into a fiber optic spectrometer for measurement.

[0063] A 980nm laser with an adjustable power of 0-30W was used to irradiate a thin film of Y₂O₃ material. By adjusting the excitation power, the Y₂O₃ material film underwent photoinduced blackbody absorption, thus producing strong optical absorption characteristics; for example... Figure 1 As shown in Figure a, Y₂O₃ thin films were excited by 980nm excitation light of different powers. When the 980nm excitation light power was greater than 22W, the excitation light power exceeded the threshold for photoinduced blackbody absorption, and the Y₂O₃ thin film suddenly emitted bright white light, while the intensity of the laser light scattered from the sample decreased synchronously. Further increasing the pump power not only increased the luminous intensity but also changed the luminous color from yellow to white.

[0064] Step 3: Measure the light absorption of the material after the photo-induced blackbody effect occurs;

[0065] The absorptivity of the material at 980 nm was obtained using a 15W 808nm laser as the excitation source. Under 808nm laser irradiation, the optical absorption at 980nm of the Y₂O₃ material thin film before and after photoinduced blackbody absorption was measured. Figure 1 As shown in d, under the irradiation of a 15W 808nm laser, the Y2O3 material sheet undergoes photoinduced blackbody absorption. The intensity of the 980nm scattered laser is significantly weaker than that without the 808nm excitation light, indicating that the material has strong optical absorption (over 90%) at 980nm.

[0066] Example 4

[0067] This embodiment provides a method for achieving intrinsic optical bistability based on the light-induced blackbody effect, specifically including the following steps:

[0068] Step 1: Preparation of Yb2O3 material thin sheets;

[0069] All chemicals were of analytical grade and required no further purification before use; yttrium oxide (Yb₂O₃, 99.99%) was supplied by Shanghai Aladdin Reagent Co., Ltd.

[0070] Place 5 mmol of oxidized powder into a tablet mold with a diameter of 12 mm, pressurize it to 8t using a BJ-15 flatbed tablet press (Tianjin, China), maintain the pressure for 20 seconds, release the pressure, and remove the tablet sample (approximately 2 mm thick).

[0071] Step 2: Select a suitable excitation source based on different materials to induce blackbody absorption;

[0072] A 980nm laser with an adjustable power of 0-30W was used to irradiate a thin film of Yb2O3 material. By adjusting the excitation light power, the thin film of Yb2O3 material underwent photoinduced blackbody absorption, thereby producing strong optical absorption characteristics. The emitted and scattered laser light from the sample was collected by optical fiber or lens group, and the collected light signal was introduced into a fiber optic spectrometer for measurement.

[0073] Step 3: Detect the wavelength range of enhanced optical absorption of the material after it is photoinduced;

[0074] To detect the wavelength range of enhanced absorption, the intensity of scattered laser light at different wavelengths was monitored. Simultaneously, a pump laser (980 nm, 30 W) and six low-power (~100 mW) probe lasers (266 nm, 405 nm, 532 nm, 650 nm, 808 nm, and 1560 nm) were irradiated onto a Yb₂O₃ thin film. When the sample underwent a photo-induced blackbody effect under the irradiation of the pump laser, the scattering intensity of the six probe lasers suddenly decreased significantly, such as... Figure 1 As shown in c, this indicates that the sample exhibits strong optical absorption over a wide spectral range. Figure 1 As shown in d, the absorption rates of the six probe lasers are all above 90%, exhibiting obvious blackbody absorption characteristics.

[0075] Example 5

[0076] This embodiment provides a method for achieving intrinsic optical bistability based on the light-induced blackbody effect, specifically including the following steps:

[0077] Step 1: Preparation of Y2O3 material thin films;

[0078] All chemicals were of analytical grade and required no further purification before use; yttrium oxide (Y₂O₃, 99.99%) was supplied by Shanghai Aladdin Reagent Co., Ltd.

[0079] Place 5 mmol of yttrium oxide powder into a 12 mm diameter tablet mold, pressurize to 8 t using a BJ-15 flatbed tablet press (Tianjin, China), maintain the pressure for 20 s, release the pressure, and remove the tablet (approximately 2 mm thick).

[0080] Step 2: Irradiate the Y₂O₃ thin film with a 980nm continuous laser with adjustable power from 0 to 30W, and focus the laser spot to ~1mm. 2 The size of the pump light was measured, and the power density of the pump light in the experiment was 0–30 W / mm². 2 The emitted and scattered laser light from the sample is collected using optical fibers or lens arrays, and the collected light signals are fed into a fiber optic spectrometer for measurement.

[0081] Step 3: As attached Figure 2 As shown in Figure a, the photon avalanche luminescence of Y₂O₃ powder exhibits significant optical bistability as the pump laser power at 980 nm increases and decreases. During the process of increasing the pump power from 0 W to 22 W, the sample does not emit light. However, as the pump power continues to increase to 22 W, the sample instantaneously enters a photoinduced blackbody state, emitting broad-spectrum incandescent light (see attached figure). Figure 4 (a) At this time, as shown in the appendix Figure 4 As shown in Figure b, the slope n = logI / logP increases instantaneously to 70.5, where I is the integrated intensity of the photoinduced blackbody radiation and P is the laser power, exhibiting avalanche luminescence characteristics. Therefore, 22W is the power threshold for the photoinduced blackbody effect in Y₂O₃ powder. As the pump power continuously increases to 30W, the luminescence intensity also continuously increases. During the period when the pump power continues to increase from 22W to 30W, the luminescence intensity increases at a relatively slow rate, with n remaining around 1.6. During the process of decreasing the pump power from 30W to 7W, the broadband luminescence of the sample continuously weakens, but it still remains in the photoinduced blackbody state. When the pump power is below 7W, the sample quickly returns to its original white color and no longer emits incandescent light. When the irradiation laser power is maintained at 7W, the photoinduced blackbody is stable under continuous radiation. Therefore, under these conditions, the minimum power required to maintain the photoinduced blackbody effect is 7W. During the rise and fall of pump power, the luminous intensity and the scattered 980nm laser follow two different paths, forming two distinct characteristics: bistable emission and bistable absorption, as shown in the attached figure. Figure 2 As shown in a. Corresponding to the luminescent bistable ring, a similar bistable phenomenon can also be found in scattered lasers, such as... Figure 2 The lower half of 'a' is shown.

[0082] Example 6

[0083] This embodiment provides a method for achieving intrinsic optical bistability based on the light-induced blackbody effect, specifically including the following steps:

[0084] Step 1: Preparation of Y2O3:0.7mol%Yb2O3 material thin sheets;

[0085] All chemicals were of analytical grade and required no further purification before use; yttrium oxide (Y₂O₃, 99.99%) and ytterbium oxide (Yb₂O₃, 99.99%) were supplied by Shanghai Aladdin Reagent Co., Ltd.

[0086] Place 5 mmol of Y2O3:0.7 mol% Yb2O3 powder into a 12 mm diameter tablet mold, pressurize to 8 t using a BJ-15 flatbed tablet press (Tianjin, China), maintain the pressure for 20 s, release the pressure, and remove the tablet (approximately 2 mm thick).

[0087] Step 2: Irradiate the Y₂O₃:0.7mol%Yb₂O₃ thin film with a 980nm continuous laser of adjustable power from 0 to 30W, with the laser spot focused to ~1mm. 2 The size of the pump light was measured, and the power density of the pump light in the experiment was 0–30 W / mm². 2 The emitted and scattered laser light from the sample is collected using optical fibers or lens arrays, and the collected light signals are fed into a fiber optic spectrometer for measurement.

[0088] Step 3: A small amount (~0.7 mol%) of Yb₂O₃ was added to the Y₂O₃ powder to increase its optical absorption at 980 nm. In this case, we still observed a clear intrinsic optical bistability. However, as... Figure 2 As shown in b, the power threshold of the mixed sample is only 13 W, far lower than that of pure Y₂O₃, while the self-sustaining power remains at 7 W, essentially unchanged. Corresponding to the luminescent bistable ring, a similar bistable phenomenon can also be observed in scattered lasers, such as... Figure 2 The lower half of b is shown. Upon entering the photoblackbody state, the optical absorption of the sample increases significantly, while the scattering of the pump laser decreases rapidly. The above experimental data indicate that the threshold power for the photoblackbody effect in a material is closely related to its initial absorption coefficient to the pump light. A larger initial absorption coefficient corresponds to a lower threshold, indicating that materials with strong optical absorption are more prone to generating the photoblackbody effect. On the other hand, there is no significant correlation between the minimum power density required to maintain the photoblackbody effect and the initial absorption coefficient of the material.

[0089] Example 7

[0090] This embodiment provides a method for achieving intrinsic optical bistability based on the light-induced blackbody effect, specifically including the following steps:

[0091] Step 1: Preparation of Yb2O3 material thin sheets;

[0092] All chemicals were of analytical grade and required no further purification before use; ytterbium oxide (Yb₂O₃, 99.99%) was supplied by Shanghai Aladdin Reagent Co., Ltd.

[0093] Place 5 mmol of Yb2O3 powder into a 12 mm diameter tablet mold, pressurize to 8 t using a BJ-15 flatbed tablet press (Tianjin, China), maintain the pressure for 20 s, release the pressure, and remove the tablet (approximately 2 mm thick).

[0094] Step 2: Two laser beams are used to irradiate the Yb₂O₃ powder sample. The excitation light is a 5W 808nm continuous laser, and the induction laser is a 980nm pulsed laser (average power 10W, repetition rate 10Hz, pulse width 40ms). Both laser beams are focused on the same point on the sample. The purpose of using a pulsed laser in this embodiment is to lengthen the time between the bistable states, allowing for better observation of the changes. If a 980nm continuous laser is used, the sample will quickly enter a photo-blackbody state. The emitted and scattered laser light from the sample is collected using optical fibers or lens arrays, and the collected light signals are fed into a fiber optic spectrometer for measurement.

[0095] Step 3: Realization of intrinsic optical bistable state. When irradiated only by a 5W 808nm laser, the sample does not produce a photo-induced blackbody effect and is in a dark state without emission; when a 980nm pulsed laser is simultaneously turned on, the sample produces new optical absorption at 808nm, and the intensity of scattered light decreases slightly. Figure 6 After approximately 10 seconds, the sample enters a photoinduced blackbody state, with a sudden increase in luminescence and a sudden decrease in scattering at 808 nm. At this point, removing the 980 nm pulsed laser allows the sample to remain stably in the photoinduced blackbody radiation state (bright state), meaning that a single 5W 808 nm laser excitation can maintain the sample in the bright state. When the 808 nm laser is momentarily blocked, the photoinduced blackbody effect immediately disappears, and the sample returns to the non-luminescent dark state under 5W 808 nm laser irradiation. This experimental result indicates that the Yb₂O₃ sample exists in two different states under 5W 808 nm laser irradiation: a dark state and a bright state. If a second laser (980 nm pulsed laser) irradiates simultaneously with the 5W 808 nm laser irradiation, the Yb₂O₃ sample will enter the bright state in a very short time; without the second laser irradiation, the sample will remain in the dark state (non-luminescent state). Briefly interrupting the 5W 808 nm laser irradiation will cause the sample to transition from the bright state to the dark state.

[0096] Example 8

[0097] This embodiment provides an application of a method for realizing intrinsic optical bistable states based on the optically induced blackbody effect in the construction of optically bistable devices, specifically including the following:

[0098] The optically bistable device based on the optically induced blackbody effect consists of an optically induced blackbody material, two laser light sources, and two photodetectors. The two laser beams illuminate the same point on the optically induced blackbody material, and the two photodetectors collect the emitted and scattered laser light from the material, respectively. The photodetector that collects the scattered laser light is configured in a mirror image with the excitation light source.

[0099] The optical bistable device can be constructed into a multi-level optical integrated device through series and parallel connections.

[0100] The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the specific details of the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the protection scope of the present invention.

[0101] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable way without contradiction. In order to avoid unnecessary repetition, the present invention will not describe the various possible combinations separately.

[0102] Furthermore, various different embodiments of the present invention can be combined in any way, as long as they do not violate the spirit of the present invention, they should also be regarded as the content disclosed by the present invention.

Claims

1. A method for achieving intrinsic optical bistable states based on the light-induced blackbody effect, characterized in that, Includes the following: Two laser beams were selected as excitation light to excite the light-induced blackbody absorbing material; The selection principles for the two laser light sources are as follows: The power of the first laser beam is P1, and the power of the second laser beam is P2, where P1 > P2. P1 and P2 are configured such that: when both laser beams simultaneously irradiate the light-induced blackbody absorbing material, a light-induced blackbody effect is generated, while when either the first laser beam or the second laser beam irradiates the light-induced blackbody absorbing material alone, no light-induced blackbody effect is generated; the wavelength of the second laser beam is consistent with the characteristic absorption wavelength of the light-induced blackbody absorbing material.

2. The method for achieving intrinsic optical bistableness based on the photoinduced blackbody effect as described in claim 1, characterized in that, The light-induced blackbody absorbing material can produce light absorption of not less than 0.1% for the second laser beam.

3. The method for achieving intrinsic optical bistableness based on the photoinduced blackbody effect as described in claim 1, characterized in that, If the light-induced blackbody absorbing material contains Yb 3+ The second laser source has a wavelength of -980 nm; if the light-induced blackbody absorbing material contains Er... 3+ The second laser source has a wavelength of -1530 nm; if the light-induced blackbody absorbing material contains Nd... 3+ The wavelength of the second laser source is -1064 nm. If the photoinduced blackbody absorbing material contains CdSe quantum dots, the wavelength of the second laser source is 400-600 nm, depending on the size of the quantum dots. This allows the material to have an absorption coefficient greater than 90% over a wide wavelength range when the photoinduced blackbody effect occurs.

4. The method for achieving intrinsic optical bistableness based on the photoinduced blackbody effect as described in claim 3, characterized in that, The wideband is 200 nm to 2500 nm.

5. The method for achieving intrinsic optical bistableness based on the photoinduced blackbody effect as described in claim 1, characterized in that, The light-induced blackbody absorbing material includes oxides, fluorides, MREF4, mixed nanostructures, or carbon-based materials; wherein M is Li, Na, K, or Ba; the oxides include Y2O3, La2O3, Lu2O3, Gd2O3, Yb2O3, ZrO2, and Y3Al5O3. 12 Ca 12 Al 14 O 33 Y2Si2O7, Y4Zr3O 12 YVO4, Sr2CeO4, Gd3Ga5O 12 Yb3Al5O 12 NdAlO3, PrO2 or BaCuSi4O 10 The fluorides include YF3, LaF3, LuF3, GaF3, or YbF3; the MREF4 includes NaYF4, LiLaF4, BaLuF4, or KGdF4; the mixed nanostructures include Ag-SiO2-Er2O3, Yb2O3 / Au, Nd2O3 / Au, or Gd2O3 / Au; and the carbon-based materials include graphene or carbon nanotubes.

6. The method for achieving intrinsic optical bistableness based on the photoinduced blackbody effect as described in claim 1, characterized in that, The method specifically includes the following steps: Step 1: Preparation of photo-induced blackbody material thin films; Place 5 mmol of Y2O3 powder into a tablet mold with a diameter of 12 mm, pressurize it to 8t using a BJ-15 flat tablet press, maintain the pressure for 20s, release the pressure, and remove the tablet sample; Step 2: Simultaneously irradiate the inducing material with two laser beams to induce a photoinduced blackbody effect; A 20 W 980 nm laser beam is focused onto a Y₂O₃ thin film, and another 5 W 980 nm laser beam is focused on the same point. When only the 20 W 980 nm laser is on, the thin film sample does not emit light. When the 5 W 980 nm laser is turned on, the Y₂O₃ thin film enters the state of photoinduced blackbody absorption and blackbody radiation. At this time, the 5 W 980 nm laser is turned off, leaving only the 20 W 980 nm laser beam to irradiate the sample, and the Y₂O₃ thin film sample remains in the state of photoinduced blackbody radiation. If the 20 W 980 nm laser is briefly blocked for less than 1 second, the Y₂O₃ thin film sample instantly exits the state of photoinduced blackbody radiation and enters a non-emitting state.

7. The application of the method for realizing intrinsic optical bistable states based on the photoinduced blackbody effect as described in claim 1 in the construction of optically bistable devices, characterized in that, The optically bistable device based on the optically induced blackbody effect consists of an optically induced blackbody material, two laser light sources, and two photodetectors. The two laser beams illuminate the same point on the optically induced blackbody material, and the two photodetectors collect the emitted and scattered laser light from the material, respectively. The photodetector that collects the scattered laser light is configured in a mirror image with the excitation light source.

8. The application of the method for realizing intrinsic optical bistable states based on the photoinduced blackbody effect as described in claim 7 in the construction of optically bistable devices, characterized in that, The optical bistable device can be constructed into a multi-level optical integrated device through series and parallel connections.

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