Single-Crystal Lithium Niobate Thin Films

Abstract

Abstract: Lithium niobate crystals have excellent electro-optic, acousto-optic and nonlinear optical properties, and have broad transmission window. As an important optical material, it is widely used in the fields of communication and sensing. Single-crystal lithium niobate thin film (lithium niobate on insulator, LNOI) prepared by ion implantation and direct bonding retains the excellent physical properties of lithium niobate bulk material, and it has large refractive index contrast. Photonic devices based on this material have been greatly improved in terms of integration and device performance. The preparation process and applications of LNOI is introduced in this paper, and a 6-inch LNOI is demonstrated. A hybrid thin film can be formed by covering a single-crystal silicon thin film on the top of a LNOI. This hybrid thin film combines the excellent optical properties of LN and excellent electronic properties of silicon. 3-inch hybrid thin film is reported in this paper. X-ray diffraction shows that the silicon thin film is single-crystal. This hybrid material will have potential applications in the future integrated optoelectronic chips.

Key words: lithium niobate, thin film, ion implantation, direct bonding, chemical mechanical polishing

CLC Number:

O734

LI Qingyun, ZHU Houbin, ZHANG Honghu, ZHANG Xiuquan, HU Hui. Single-Crystal Lithium Niobate Thin Films[J]. JOURNAL OF SYNTHETIC CRYSTALS, 2021, 50(4): 716-723.

References

[1] SCHMIDT R V, KAMINOW I P. Metal-diffused optical waveguides in LiNbO₃[J]. Applied Physics Letters, 1974, 25(8): 458-460.
[2] BORTZ M L, FEJER M M. Annealed proton-exchanged LiNbO₃ waveguides[J]. Optics Letters, 1991, 16(23): 1844-1846.
[3] JACKEL J L, RICE C E, VESELKA J J. Proton exchange for high-index waveguides in LiNbO₃[J]. Applied Physics Letters, 1982, 41(7): 607-608.
[4] CHEN F. Photonic guiding structures in lithium niobate crystals produced by energetic ion beams[J]. Journal of Applied Physics, 2009, 106(8): 081101.
[5] NAKATA Y, GUNJI S, OKADA T, et al. Fabrication of LiNbO₃ thin films by pulsed laser deposition and investigation of nonlinear properties[J]. Applied Physics A, 2004, 79(4/5/6): 1279-1282.
[6] YOON J G, KIM K. Growth of highly textured LiNbO₃ thin film on Si with MgO buffer layer through the sol-gel process[J]. Applied Physics Letters, 1996, 68(18): 2523-2525.
[7] LANSIAUX X, DOGHECHE E, REMIENS D, et al. LiNbO₃ thick films grown on sapphire by using a multistep sputtering process[J]. Journal of Applied Physics, 2001, 90(10): 5274-5277.
[8] SAKASHITA Y, SEGAWA H. Preparation and characterization of LiNbO₃thin films produced by chemical-vapor deposition[J]. Journal of Applied Physics, 1995, 77(11): 5995-5999.
[9] BRUEL M. Silicon on insulator material technology[J]. Electronics Letters, 1995, 31(14): 1201.
[10] LEVY M, OSGOOD R M Jr, LIU R, et al. Fabrication of single-crystal lithium niobate films by crystal ion slicing[J]. Applied Physics Letters, 1998, 73(16): 2293-2295.
[11] RABIEI P, GUNTER P. Optical and electro-optical properties of submicrometer lithium niobate slab waveguides prepared by crystal ion slicing and wafer bonding[J]. Applied Physics Letters, 2004, 85(20): 4603-4605.
[12] DJUKIC D, CERDA-PONS G, ROTH R M, et al. Electro-optically tunable second-harmonic-generation gratings in ion-exfoliated thin films of periodically poled lithium niobate[J]. Applied Physics Letters, 2007, 90(17): 171116.
[13] WANG T J, CHU C H, LIN C Y. Electro-optically tunable microring resonators on lithium niobate[J]. Optics Letters, 2007, 32(19): 2777-2779.
[14] RAMADAN T A, LEVY M, OSGOOD R M Jr. Electro-optic modulation in crystal-ion-sliced z-cut LiNbO₃ thin films[J]. Applied Physics Letters, 2000, 76(11): 1407-1409.
[15] ROTH R M, DJUKIC D, LEE Y S, et al. Compositional and structural changes in LiNbO₃ following deep He⁺ ion implantation for film exfoliation[J]. Applied Physics Letters, 2006, 89(11): 112906.
[16] LI X J, TERABE K, HATANO H, et al. Domain patterning thin crystalline ferroelectric film with focused ion beam for nonlinear photonic integrated circuits[J]. Journal of Applied Physics, 2006, 100(10): 106103.
[17] POBERAJ G, HU H, SOHLER W, et al. Lithium niobate on insulator (LNOI) for micro-photonic devices[J]. Laser & Photonics Reviews, 2012, 6(4): 488-503.
[18] 韩黄璞.单晶铌酸锂薄膜的结构和属性研究[D].济南:山东大学,2016:34-52.
HAN H P. Structure and properties of single crystal LiNbO₃ thin films[D]. Jinan: Shandong University, 2016: 34-52(in Chinese).
[19] SUBBARAMAN H, XU X C, HOSSEINI A, et al. Recent advances in silicon-based passive and active optical interconnects[J]. Optics Express, 2015, 23(3): 2487-2511.
[20] KOMLJENOVIC T, DAVENPORT M, HULME J, et al. Heterogeneous silicon photonic integrated circuits[J]. Journal of Lightwave Technology, 2016, 34(1): 20-35.
[21] TROIA B, PENADES J S, QU Z B, et al. Silicon ring resonator-coupled Mach-Zehnder interferometers for the Fano resonance in the mid-IR[J]. Applied Optics, 2017, 56(31): 8769-8776.
[22] LEE Y S, KIM G D, KIM W J, et al. Hybrid Si-LiNbO₃ microring electro-optically tunable resonators for active photonic devices[J]. Optics Letters, 2011, 36(7): 1119-1121.
[23] CHEN L, CHEN J H, NAGY J, et al. Highly linear ring modulator from hybrid silicon and lithium niobate[J]. Optics Express, 2015, 23(10): 13255-13264.
[24] WEIGEL P O, SAVANIER M, DEROSE C T, et al. Lightwave circuits in lithium niobate through hybrid waveguides with silicon photonics[J]. Sci Rep, 2016, 6: 22301.
[25] WANG Y W, CHEN Z H, CAI L T, et al. Amorphous silicon-lithium niobate thin film strip-loaded waveguides[J]. Optical Materials Express, 2017, 7(11): 4018-4028.
[26] CAI L, KONG R, WANG Y, et al. Channel waveguides and y-junctions in x-cut single-crystal lithium niobate thin film[J]. Optics Express, 2015, 23(22): 29211-29221.
[27] CAI L T, WANG Y W, HU H. Low-loss waveguides in a single-crystal lithium niobate thin film[J]. Optics Letters, 2015, 40(13): 3013-3016.
[28] LUO R, HE Y, LIANG H X, et al. Semi-nonlinear nanophotonic waveguides for highly efficient second-harmonic generation[J]. Laser & Photonics Reviews, 2019, 13(3): 1800288.
[29] LI S, CAI L T, WANG Y W, et al. Waveguides consisting of single-crystal lithium niobate thin film and oxidized titanium stripe[J]. Optics Express, 2015, 23(19): 24212-24219.
[30] 王羿文.铌酸锂单晶薄膜上加载条型波导和集成光学器件的研究[D].济南:山东大学,2019:62-67.
WANG Y W. Study on loaded strip waveguides and integrated optical devices on LiNbO₃ single crystal films[D]. Jinan: Shandong University, 2019: 62-67(in Chinese).
[31] JIN S L, XU L T, ZHANG H H, et al. LiNbO₃ thin-film modulators using silicon nitride surface ridge waveguides[J]. IEEE Photonics Technology Letters, 2016, 28(7): 736-739.
[32] RAO A, MALINOWSKI M, HONARDOOST A, et al. Second-harmonic generation in periodically-poled thin film lithium niobate wafer-bonded on silicon[J]. Optics Express, 2016, 24(26): 29941-29947.
[33] CHANG L, PFEIFFER M H P, VOLET N, et al. Heterogeneous integration of lithium niobate and silicon nitride waveguides for wafer-scale photonic integrated circuits on silicon[J]. Optics Letters, 2017, 42(4): 803-806.
[34] RABIEI P, MA J, KHAN S, et al. Heterogeneous lithium niobate photonics on silicon substrates[J]. Optics Express, 2013, 21(21): 25573-25581.
[35] RAO A, PATIL A, CHILES J, et al. Heterogeneous microring and Mach-Zehnder modulators based on lithium niobate and chalcogenide glasses on silicon[J]. Optics Express, 2015, 23(17): 22746-22752.
[36] CHEN L, WOOD M G, REANO R M. 12.5 pm/V hybrid silicon and lithium niobate optical microring resonator with integrated electrodes[J]. Optics Express, 2013, 21(22): 27003-27010.
[37] ZHANG M, WANG C, CHENG R, et al. Monolithic ultra-high-Q lithium niobate microring resonator[J]. Optica, 2017, 4(12): 1536-1537.
[38] WANG M, WU R B, LIN J T, et al. Chemo-mechanical Polish lithography: a pathway to low loss large-scale photonic integration on lithium niobate on insulator[J]. Quantum Engineering, 2019, 1(1): e9.
[39] KANG S T, ZHANG R, HAO Z Z, et al. High-efficiency chirped grating couplers on lithium niobate on insulator[J]. Optics Letters, 2020, 45(24): 6651-6654.
[40] HE L Y, HE L Y, ZHANG M, et al. Low-loss fiber-to-chip interface for lithium niobate photonic integrated circuits[J]. Optics Letters, 2019, 44(9): 2314-2317.
[41] YONEKURA K, JIN L H, TAKIZAWA K. Measurement of dispersion of effective electro-optic Coefficients γ^E₁₃ and γ^E₃₃ of non-doped congruent LiNbO₃Crystal[J]. Japanese Journal of Applied Physics, 2008, 47(7): 5503-5508.
[42] CAI L, KANG Y, HU H. Electric-optical property of the proton exchanged phase modulator in single-crystal lithium niobate thin film[J]. Optics Express, 2016, 24(5): 4640-4647.
[43] MERCANTE A J, SHI S Y, YAO P, et al. Thin film lithium niobate electro-optic modulator with terahertz operating bandwidth[J]. Optics Express, 2018, 26(11): 14810-14816.
[44] REN T H, ZHANG M, WANG C, et al. An integrated low-voltage broadband lithium niobate phase modulator[J]. IEEE Photonics Technology Letters, 2019, 31(11): 889-892.
[45] MERCANTE A J, YAO P, SHI S Y, et al. 110 GHz CMOS compatible thin film LiNbO₃ modulator on silicon[J]. Optics Express, 2016, 24(14): 15590-15595.
[46] WANG C, ZHANG M, CHEN X, et al. Integrated lithium niobate electro-optic modulators operating at CMOS-compatible voltages[J]. Nature, 2018, 562(7725): 101-104.
[47] XU M, HE M, ZHANG H, et al. High-performance coherent optical modulators based on thin-film lithium niobate platform[J]. Nature Communications, 2020, 11(1): 3911.
[48] WANG C, ZHANG M, STERN B, et al. Nanophotonic lithium niobate electro-optic modulators[J]. Optics Express, 2018, 26(2): 1547-1555.
[49] LIN J T, YAO N, HAO Z Z, et al. Broadband quasi-phase-matched harmonic generation in an on-chip monocrystalline lithium niobate microdisk resonator[J]. Physical Review Letters, 2019, 122(17): 173903.
[50] YU M J, DESIATOV B, OKAWACHI Y, et al. Coherent two-octave-spanning supercontinuum generation in lithium-niobate waveguides[J]. Optics Letters, 2019, 44(5): 1222-1225.
[51] ZHANG M, WANG C, HU Y W, et al. Electronically programmable photonic molecule[J]. Nature Photonics, 2019, 13(1): 36-40.
[52] LIN J, XU Y, FANG Z, et al. Fabrication of high-Q lithium niobate microresonators using femtosecond laser micromachining for second harmonic generation[J]. 2015: STh3M.3.
[53] WANG J, BO F, WAN S, et al. High-Q lithium niobate microdisk resonators on a chip for efficient electro-optic modulation[J]. Optics Express, 2015, 23(18): 23072-23078.
[54] JIANG W C, LIN Q. Chip-scale cavity optomechanics in lithium niobate[J]. Scientific Reports, 2016, 6: 36920.
[55] YE X N, LIU S J, CHEN Y P, et al. Sum-frequency generation in lithium-niobate-on-insulator microdisk via modal phase matching[J]. Optics Letters, 2020, 45(2): 523-526.
[56] SASAGAWA K, TSUCHIYA M. Highly efficient third harmonic generation in a periodically poled MgO:LiNbO₃disk resonator[J]. Applied Physics Express, 2009, 2(12): 122401.
[57] LIU S J, LIU S J, ZHENG Y L, et al. Cascading second-order nonlinear processes in a lithium niobate-on-insulator microdisk[J]. 2018: NpTh1C.3.
[58] GAINUTDINOV R V, VOLK T R, ZHANG H H. Domain formation and polarization reversal under atomic force microscopy-tip voltages in ion-sliced LiNbO₃ films on SiO₂/LiNbO₃ substrates[J]. Applied Physics Letters, 2015, 107(16): 162903.
[59] MACKWITZ P, RÜSING M, BERTH G, et al. Periodic domain inversion in x-cut single-crystal lithium niobate thin film[J]. Applied Physics Letters, 2016, 108(15): 152902.
[60] LU J J, SURYA J B, LIU X W, et al. Periodically poled thin-film lithium niobate microring resonators with a second-harmonic generation efficiency of 250, 000%/W[J]. Optica, 2019, 6(12): 1455-1460.
[61] SHAO L B, YU M J, MAITY S, et al. Microwave-to-optical conversion using lithium niobate thin-film acoustic resonators[J]. Optica, 2019, 6(12): 1498.
[62] SARABALIS C J, MCKENNA T P, PATEL R N, et al. Acousto-optic modulation in lithium niobate on sapphire[J]. APL Photonics, 2020, 5(8): 086104.
[63] ZHU D, SHAO L B, YU M J, et al. Integrated photonics on thin-film lithium niobate[EB/OL]. 2102.11956[physics.optics]. https: //arxiv.org/abs/2102.11956.