Use of lanthanide metal crystals in the production of nonlinear optical devices or birefringent optical devices

Abstract

The application discloses application of a lanthanide metal crystal in preparation of a nonlinear optical device or a birefringent optical device. The lanthanide metal crystal is selected from La4O4Se3, Ce4O4Se3, Pr4O4Se3, Nd4O4Se3 or Sm4O4Se3. In the application, a specific lanthanide metal crystal is used in preparation of a nonlinear optical device, and a nonlinear optical device with sufficient nonlinear optical effect and a long infrared cutoff edge capable of covering an atmospheric transparent window of 8-14 microns is obtained.

Description

Technical Field

[0001] This invention relates to the field of nonlinear optical device technology. More specifically, it relates to the application of a lanthanide metal crystal in the fabrication of nonlinear optical devices or birefringent optical devices. Background Technology

[0002] Nonlinear optical crystals are crucial components of all-solid-state laser technology. They can utilize nonlinear optical effects to convert laser frequencies and, through multi-stage frequency conversion techniques, convert near-infrared lasers to new wavelengths, achieving laser output in the ultraviolet, deep ultraviolet, infrared, mid-far-infrared, and even terahertz bands. These crystals possess advantages such as high conversion efficiency, tunability, good beam quality, and miniaturization, making them important in fields like spectroscopy, quantum optics, communications and optical computing, bioimaging, and precision manufacturing. On the other hand, birefringent optical materials are also widely used in optoelectronic devices such as polarization optics, optical switches, optical isolation, and optical modulation. These materials can achieve polarization manipulation of beams through birefringence, playing a key role in devices such as isolators, waveplates, and modulators. Infrared lasers with wavelengths in the 3-5 micrometer and 8-12 micrometer "atmospheric windows" have significant application prospects in civilian and military fields such as laser medicine, infrared communication, infrared detection, laser guidance, and military countermeasures. Currently, one of the important approaches to obtaining lasers in this wavelength range (mid-infrared) is to utilize nonlinear optical crystals to perform frequency conversion on lasers in the visible or near-infrared bands. This can be achieved through methods such as optical parametric oscillation or optical parametric amplification, extending near-infrared lasers (1064 nm) into the mid-infrared region. Currently, laser frequency conversion technology in this band primarily utilizes chalcopyrite-type nonlinear optical materials, such as AgGaS2 and ZnGeP2 series crystals. However, their low laser damage threshold and severe multiphoton absorption limit their application in high-power lasers in the mid-infrared band. Therefore, exploring high-performance mid-infrared nonlinear optical crystal materials has become a cutting-edge research area in the field of nonlinear materials.

[0003] The technical challenges faced by AgGaS2 and ZnGeP2 series crystals are twofold: firstly, their inherent defects severely hinder higher-power laser output; and secondly, AgGaS2 and ZnGeP2 exhibit strong multiphonon absorption near 9 μm, failing to cover the atmospheric transparency window of 8-14 μm. Therefore, finding new infrared nonlinear optical materials that possess both sufficient nonlinear optical effects and a long infrared cutoff edge has become a key scientific problem to be solved. Summary of the Invention

[0004] To address the aforementioned technical problems, the present invention aims to provide an application of lanthanide metal crystals in the fabrication of nonlinear optical devices. In this invention, specific lanthanide metal crystals are used in the fabrication of nonlinear optical devices, resulting in nonlinear optical devices with sufficient nonlinear optical effects, a relatively long infrared cutoff edge, and the ability to cover an atmospheric transparency window of 8-14 μm.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] On one hand, the present invention provides the application of lanthanide metal crystals in the preparation of nonlinear optical devices or birefringent optical devices, wherein the lanthanide metal crystals are selected from La4O4Se3 crystals, Ce4O4Se3 crystals, Pr4O4Se3 crystals, Nd4O4Se3 crystals or Sm4O4Se3 crystals.

[0007] Furthermore, the La4O4Se3 crystal belongs to the orthorhombic crystal system, with space group Amm2 and cell parameter a = 8.579. α=β=γ=90°, Z=2, unit cell volume is

[0008] Furthermore, the Ce4O4Se3 crystal belongs to the orthorhombic crystal system, with space group Amm2 and cell parameters of [missing information]. α=β=γ=90°, Z=2, unit cell volume is

[0009] Furthermore, the Pr4O4Se3 crystal belongs to the orthorhombic crystal system, with space group Amm2 and cell parameter a = 8.499. α=β=γ=90°, Z=2, unit cell volume is

[0010] Furthermore, the Nd4O4Se3 crystal belongs to the orthorhombic crystal system, with space group Amm2 and cell parameter a = 8.457. α=β=γ=90°, Z=2, unit cell volume is

[0011] Furthermore, the Sm4O4Se3 crystal belongs to the orthorhombic crystal system, with space group Amm2 and cell parameter a = 8.401. α=β=γ=90°, Z=2, unit cell volume is

[0012] The lanthanide crystals provided by this invention exhibit high second-order nonlinear optical effects and large birefringence. For example, the second-order nonlinear optical effect of La4O4Se3 crystal is approximately twice that of practical AgGaS2 crystal, with an optical band gap of approximately 2.0 eV, an infrared transmission cutoff edge reaching 23 μm, and a birefringence as high as 0.66 at 10 μm. These crystals demonstrate excellent performance in nonlinear or birefringent optical devices. Furthermore, these crystals can be widely used in various nonlinear optical fields, especially in the mid-infrared band and in birefringent optics.

[0013] Furthermore, the application includes the following steps:

[0014] The nonlinear optical device or birefringent optical device is obtained by orienting, cutting, polishing and coating the light-transmitting surface of the lanthanide metal crystal.

[0015] Furthermore, when at least one incident electromagnetic radiation beam passes through the nonlinear optical device or birefringent optical device, at least one electromagnetic radiation beam with a frequency different from the incident electromagnetic radiation beam will be generated.

[0016] Furthermore, the nonlinear optical device or birefringent optical device is selected from laser frequency conversion devices or electro-optic devices.

[0017] Furthermore, the laser frequency conversion device is a frequency doubling laser frequency conversion device, an optical parametric oscillator device, or an optical parametric amplifier device.

[0018] Furthermore, the nonlinear optical device or birefringent optical device is an infrared band frequency doubling laser frequency converter, an electro-optic device, or an optical parametric amplifier device.

[0019] Furthermore, the frequency doubling laser frequency conversion device is selected from a harmonic generator.

[0020] Furthermore, the nonlinear optical device or birefringent optical device is a laser frequency conversion device in the mid-infrared band.

[0021] Furthermore, the nonlinear optical device or birefringent optical device is an electro-optic device in the mid-infrared band.

[0022] The beneficial effects of this invention are as follows:

[0023] In this invention, a lanthanide metal crystal with a specific structure is used in the fabrication of a nonlinear optical device. This results in a stable nonlinear optical device with a large nonlinear optical coefficient, which is beneficial for achieving efficient frequency conversion. Furthermore, it possesses a large birefringence coefficient, which is advantageous for applications such as light wave decomposition and modulation. Moreover, the fabrication of this nonlinear optical device is simple and easy to implement. Attached Figure Description

[0024] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.

[0025] Figure 1 The UV-Vis diffuse reflectance spectrum of polycrystalline La4O4Se3 powder is shown.

[0026] Figure 2 The X-ray diffraction spectra of La4O4Se3 crystals obtained from experimental and theoretical simulations are shown.

[0027] Figure 3 The infrared transmission spectrum of La4O4Se3 crystal is shown. Detailed Implementation

[0028] To more clearly illustrate the present invention, the following description, in conjunction with preferred embodiments and accompanying drawings, further explains the invention. Similar components in the drawings are indicated by the same reference numerals. Those skilled in the art should understand that the specific description below is illustrative rather than restrictive and should not be construed as limiting the scope of protection of the present invention.

[0029] A series of single-crystal samples of Ln4O4Se3 (Ln=La, Ce, Pr, Nd, Sm) were prepared using a solid-state high-temperature method. The specific steps are as follows:

[0030] (1) According to the synthesis method described in Inorg. Chem. 2008, 47, 4936-4944, Ln4O4Se3 (Ln = La, Ce, Pr, Nd, Sm) series of powder polycrystalline samples were prepared: La, Se and SeO2 were mixed in a molar ratio of 4:1:2, the raw materials were sealed in a quartz tube, and calcined at a certain temperature (750-1000℃) for 24 h to obtain Ln4O4Se3 (Ln = La, Ce, Pr, Nd, Sm) series of powder polycrystalline samples; among them, the ultraviolet-visible diffuse reflectance spectrum of the obtained La4O4Se3 powder polycrystalline sample is as follows: Figure 1 As shown;

[0031] (2) Mix Ln4O4Se3 (Ln=La,Ce,Pr,Nd,Sm) series polycrystalline powder with 5 times the weight of CsCl flux and seal it in a quartz tube. Keep it at 1000℃ for 24h and cool it down at a rate of 8.3℃ / h.

[0032] (3) The sample obtained in step (2) is washed and dried with deionized water to obtain flaky brownish-green Ln4O4Se3 (Ln = La, Ce, Pr, Nd, Sm) series crystals; among which, the experimental and theoretical simulated X-ray diffraction spectra of La4O4Se3 crystals are as follows: Figure 2 As shown; the infrared transmission spectrum of La4O4Se3 crystal is as follows. Figure 3 As shown.

[0033] Among them, using single-crystal X-ray diffraction testing, it can be seen that in the crystal obtained in step (3) above:

[0034] La4O4Se3 crystal belongs to the orthorhombic crystal system, space group Amm2, and cell parameter a = 8.579. α=β=γ=90°, Z=2, unit cell volume is

[0035] Ce4O4Se3 crystal belongs to the orthorhombic crystal system, space group Amm2, and its unit cell parameter is... α=β=γ=90°, Z=2, unit cell volume is

[0036] Pr4O4Se3 crystal belongs to the orthorhombic crystal system, space group Amm2, and cell parameter a = 8.499. α=β=γ=90°, Z=2, unit cell volume is

[0037] Nd₄O₄Se₃ crystal belongs to the orthorhombic crystal system, space group Amm², and has a cell parameter of a = 8.457. α=β=γ=90°, Z=2, unit cell volume is

[0038] Sm4O4Se3 crystal belongs to the orthorhombic crystal system, space group Amm2, and cell parameter a = 8.401. α=β=γ=90°, Z=2, unit cell volume is

[0039] The optical properties of the La4O4Se3 crystal were calculated using mature and reliable first-principles calculation simulation methods. To demonstrate the applicability of the theoretical calculation results described in this invention, the calculation results of the known mid-infrared nonlinear optical crystal AgGaS2 are listed as a reference. The calculation results are shown in Table 1, which lists the experimentally measured and theoretically calculated nonlinear optical properties of AgGaS2 and La4O4Se3 crystals.

[0040] Table 1

[0041]

[0042]

[0043] As can be seen from Table 1, the nonlinear optical properties of the crystal obtained by the method provided by the present invention are almost consistent with the experimental values. Therefore, the optical performance data obtained by the theoretical calculation method provided by the present invention are true and valid and can be used as a reference.

[0044] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. For those skilled in the art, other variations or modifications can be made based on the above description. It is impossible to exhaustively list all the implementation methods here. All obvious variations or modifications derived from the technical solutions of the present invention are still within the protection scope of the present invention.

Claims

1. The application of lanthanide metal crystals in the fabrication of nonlinear optical devices or birefringent optical devices, characterized in that, The lanthanide metal crystals are selected from La4O4Se3 crystals, Ce4O4Se3 crystals, Pr4O4Se3 crystals, Nd4O4Se3 crystals, or Sm4O4Se3 crystals.

2. The application according to claim 1, characterized in that, The La4O4Se3 crystal belongs to the orthorhombic crystal system, with space group Amm2 and cell parameter a = 8.

579. α=β=γ=90°, Z=2, unit cell volume is The Ce4O4Se3 crystal belongs to the orthorhombic crystal system, with space group Amm2 and cell parameters of [missing information]. b = 4.048 α=β=γ=90°, Z=2, unit cell volume is The Pr4O4Se3 crystal belongs to the orthorhombic crystal system, with space group Amm2 and cell parameter a = 8.

499. α=β=γ=90°, Z=2, unit cell volume is The Nd4O4Se3 crystal belongs to the orthorhombic crystal system, with space group Amm2 and cell parameter a = 8.

457. α=β=γ=90°, Z=2, unit cell volume is The Sm4O4Se3 crystal belongs to the orthorhombic crystal system, with space group Amm2 and cell parameter a = 8.

401. α=β=γ=90°, Z=2, unit cell volume is 3. The application according to claim 1 or 2, characterized in that, The application includes the following steps: The nonlinear optical device or birefringent optical device is obtained by orienting, cutting, polishing and coating the light-transmitting surface of the lanthanide metal crystal.

4. The application according to claim 3, characterized in that, When at least one incident electromagnetic radiation passes through the nonlinear optical device or birefringent optical device, at least one electromagnetic radiation with a frequency different from the incident electromagnetic radiation will be generated.

5. The application according to claim 1, characterized in that, The nonlinear optical device or birefringent optical device is selected from laser frequency conversion devices or electro-optic devices.

6. The application according to claim 5, characterized in that, The laser frequency conversion device is a frequency doubling laser frequency conversion device, an optical parametric oscillator, or an optical parametric amplifier.

7. The application according to claim 5, characterized in that, The nonlinear optical device or birefringent optical device is an infrared band frequency doubling laser frequency converter, an electro-optic device, or an optical parametric amplifier.

8. The application according to claim 7, characterized in that... The frequency doubling laser frequency conversion device is selected from a harmonic generator.

9. The application according to claim 5, characterized in that, The nonlinear optical device or birefringent optical device is a laser frequency conversion device in the mid-infrared band.

10. The application according to claim 5, characterized in that, The nonlinear optical device or birefringent optical device is an electro-optic device in the mid-infrared band.

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