[1] Sun X Y, Wang Y Y, Zhong L J et al. High-order mode waveguide amplifier with high mode extinction ratio written in an Er3+-doped phosphate glass[J]. Optics Express, 31, 5812-5819(2023).
[2] Wang Y Y, Zhong L J, Chen Z et al. Photonic lattice-like waveguides in glass directly written by femtosecond laser for on-chip mode conversion[J]. Chinese Optics Letters, 20, 031406(2022).
[3] Sun B S, Morozko F, Salter P S et al. On-chip beam rotators, adiabatic mode converters, and waveplates through low-loss waveguides with variable cross-sections[J]. Light: Science & Applications, 11, 214(2022).
[4] Wang H, Zhang W, Ladika D et al. Two-photon polymerization lithography for optics and photonics: fundamentals, materials, technologies, and applications[J]. Advanced Functional Materials, 2214211(2023).
[5] LaFratta C N, Fourkas J T, Baldacchini T et al. Multiphoton fabrication[J]. Angewandte Chemie (International Ed. in English), 46, 6238-6258(2007).
[6] Han X Y, Wu Z L, Yang S C et al. Recent progress of imprinted polymer photonic waveguide devices and applications[J]. Polymers, 10, 603(2018).
[7] Ma H, Jen A K Y, Dalton L R. Polymer-based optical waveguides: materials, processing, and devices[J]. Advanced Materials, 14, 1339-1365(2002).
[8] Nieweglowski K, Lorenz L, Lüngen S et al. Optical coupling with flexible polymer waveguides for chip-to-chip interconnects in electronic systems[J]. Microelectronics Reliability, 84, 121-126(2018).
[9] Dangel R, Hofrichter J, Horst F et al. Polymer waveguides for electro-optical integration in data centers and high-performance computers[J]. Optics Express, 23, 4736-4750(2015).
[10] Soma K, Ishigure T. Fabrication of a graded-index circular-core polymer parallel optical waveguide using a microdispenser for a high-density optical printed circuit board[J]. IEEE Journal of Selected Topics in Quantum Electronics, 19, 3600310(2013).
[11] Dangel R, Berger C, Beyeler R et al. Polymer-waveguide-based board-level optical interconnect technology for datacom applications[J]. IEEE Transactions on Advanced Packaging, 31, 759-767(2008).
[12] Choi C, Lin L, Liu Y J et al. Flexible optical waveguide film fabrications and optoelectronic devices integration for fully embedded board-level optical interconnects[J]. Journal of Lightwave Technology, 22, 2168-2176(2004).
[13] Parks J W, Schmidt H. Flexible optofluidic waveguide platform with multi-dimensional reconfigurability[J]. Scientific Reports, 6, 33008(2016).
[14] Yetisen A K, Jiang N, Fallahi A et al. Glucose-sensitive hydrogel optical fibers functionalized with phenylboronic acid[J]. Advanced Materials, 29, 1606380(2017).
[15] Choi M, Humar M, Kim S et al. Step-index optical fiber made of biocompatible hydrogels[J]. Advanced Materials, 27, 4081-4086(2015).
[16] Zeng W, Shu L, Li Q et al. Fiber-based wearable electronics: a review of materials, fabrication, devices, and applications[J]. Advanced Materials, 26, 5310-5336(2014).
[17] Guo J J, Zhou B Q, Yang C X et al. Stretchable and temperature-sensitive polymer optical fibers for wearable health monitoring[J]. Advanced Functional Materials, 29, 1902898(2019).
[18] Park S, Guo Y Y, Jia X T et al. One-step optogenetics with multifunctional flexible polymer fibers[J]. Nature Neuroscience, 20, 612-619(2017).
[19] Jorfi M, Voirin G, Foster E J et al. Physiologically responsive, mechanically adaptive polymer optical fibers for optogenetics[J]. Optics Letters, 39, 2872-2875(2014).
[20] Wang Z, El-Ali J, Engelund M et al. Measurements of scattered light on a microchip flow cytometer with integrated polymer based optical elements[J]. Lab on a Chip, 4, 372-377(2004).
[21] Cai Z L, Qiu W P, Shao G C et al. A new fabrication method for all-PDMS waveguides[J]. Sensors and Actuators A: Physical, 204, 44-47(2013).
[22] Kee J S, Poenar D P, Neuzil P et al. Design and fabrication of Poly(dimethylsiloxane) single-mode rib waveguide[J]. Optics Express, 17, 11739-11746(2009).
[23] Chang-Yen D A, Eich R K, Gale B K. A monolithic PDMS waveguide system fabricated using soft-lithography techniques[J]. Journal of Lightwave Technology, 23, 2088-2093(2005).
[24] Gattass R R, Mazur E. Femtosecond laser micromachining in transparent materials[J]. Nature Photonics, 2, 219-225(2008).
[25] Poulin J, Kashyap R. Novel tuneable on-fiber polymeric phase-mask for fiber and planar waveguide Bragg grating fabrication[J]. Optics Express, 13, 4414-4419(2005).
[26] Potter B G, Simmons-Potter K, Chandra H et al. Photoprogrammable molecular hybrid materials for write-as-needed optical devices[J]. Journal of Non-Crystalline Solids, 352, 2618-2627(2006).
[27] Panusa G, Pu Y, Wang J P et al. Photoinitiator-free multi-photon fabrication of compact optical waveguides in polydimethylsiloxane[J]. Optical Materials Express, 9, 128-138(2018).
[28] Panusa G, Pu Y, Wang J P et al. Fabrication of sub-micron polymer waveguides through two-photon polymerization in polydimethylsiloxane[J]. Polymers, 12, 2485(2020).
[29] Panusa G. Three-dimensional fabrication of sub-micron optical waveguides in PDMS and other polymer materials[D], 1-146(2021).
[30] Boisvert J S, Hlil A, Hassan I et al. Photosensitised PDMS for femtosecond laser writing[J]. OSA Continuum, 3, 1334-1345(2020).
[31] Boisvert J S, Hlil A, Loranger S et al. Photosensitization agents for fs laser writing in PDMS[J]. Scientific Reports, 12, 1623(2022).
[32] Couairon A, Sudrie L, Franco M et al. Filamentation and damage in fused silica induced by tightly focused femtosecond laser pulses[J]. Physical Review B, 71, 125435(2005).
[33] Thomson R R, Campbell S, Blewett I J et al. Optical waveguide fabrication in z-cut lithium niobate (LiNbO3) using femtosecond pulses in the low repetition rate regime[J]. Applied Physics Letters, 88, 111109(2006).
[34] Tu C H, Huang Z C, Zhang S G et al. Second harmonic generation by femtosecond Yb-doped fiber laser source based on PPKTP waveguide fabricated by femtosecond laser direct writing[J]. Optics Communications, 284, 455-459(2011).
[35] Zhang L, Miao F, Feng D J et al. Exposure experiment study of fiber Bragg grating by femtosecond laser[J]. Chinese Journal of Lasers, 38, 0505006(2011).
[36] Meany T, Gräfe M, Heilmann R et al. Laser written circuits for quantum photonics[J]. Laser & Photonics Reviews, 9, 363-384(2015).
[37] Chen F, de Aldana J R V. Optical waveguides in crystalline dielectric materials produced by femtosecond-laser micromachining[J]. Laser & Photonics Reviews, 8, 251-275(2014).
[38] Taylor R, Hnatovsky C, Simova E. Applications of femtosecond laser induced self-organized planar nanocracks inside fused silica glass[J]. Laser & Photonics Review, 2, 26-46(2008).
[39] Miura K, Qiu J R, Inouye H et al. Photowritten optical waveguides in various glasses with ultrashort pulse laser[J]. Applied Physics Letters, 71, 3329-3331(1997).
[40] Hirao K, Miura K. Writing waveguides and gratings in silica and related materials by a femtosecond laser[J]. Journal of Non-Crystalline Solids, 239, 91-95(1998).
[41] Chan J W, Huser T, Risbud S et al. Structural changes in fused silica after exposure to focused femtosecond laser pulses[J]. Optics Letters, 26, 1726-1728(2001).
[42] Ponader C W, Schroeder J F, Streltsov A M. Origin of the refractive-index increase in laser-written waveguides in glasses[J]. Journal of Applied Physics, 103, 063516(2008).
[43] Efimov O M, Glebov L B, Richardson K A et al. Waveguide writing in chalcogenide glasses by a train of femtosecond laser pulses[J]. Optical Materials, 17, 379-386(2001).
[44] Fletcher L B, Witcher J J, Reichman W B et al. Changes to the network structure of Er-Yb doped phosphate glass induced by femtosecond laser pulses[J]. Journal of Applied Physics, 106, 083107(2009).
[45] Bellouard Y, Barthel E, Said A A et al. Scanning thermal microscopy and Raman analysis of bulk fused silica exposed to lowenergy femtosecond laser pulses[J]. Optics Express, 16, 19520-19534(2008).
[46] Streltsov A M, Borrelli N F. Study of femtosecond-laser-written waveguides in glasses[J]. Journal of the Optical Society of America B, 19, 2496-2504(2002).
[47] Haken U, Humbach O, Ortner S et al. Refractive index of silica glass: influence of fictive temperature[J]. Journal of Non-Crystalline Solids, 265, 9-18(2000).
[48] Gross T M, Tomozawa M. Fictive temperature of GeO2 glass: its determination by IR method and its effects on density and refractive index[J]. Journal of Non-Crystalline Solids, 353, 4762-4766(2007).
[49] Bressel L, de Ligny D, Sonneville C et al. Femtosecond laser induced density changes in GeO2 and SiO2 glasses: fictive temperature effect[J]. Optical Materials Express, 1, 605-613(2011).
[50] Reichman W, Click C A, Krol D M. Femtosecond laser writing of waveguide structures in sodium calcium silicate glasses[J]. Proceedings of SPIE, 5714, 238-244(2005).
[51] Ams M, Marshall G D, Dekker P et al. Investigation of ultrafast laser: photonic material interactions: challenges for directly written glass photonics[J]. IEEE Journal of Selected Topics in Quantum Electronics, 14, 1370-1381(2008).
[52] Petite G, Guizard S, Martin P et al. Comment on “ultrafast electron dynamics in femtosecond optical breakdown of dielectrics”[J]. Physical Review Letters, 83, 5182(1999).
[53] Poumellec B, Lancry M, Chahid-Erraji A et al. Modification thresholds in femtosecond laser processing of pure silica: review of dependencies on laser parameters[J]. Optical Materials Express, 1, 766-782(2011).
[54] Kurobori T, Kawamura K I, Hirano M et al. Simultaneous fabrication of laser-active colour centres and permanent microgratings in lithium fluoride by a single femtosecond pulse[J]. Journal of Physics: Condensed Matter, 15, L399-L405(2003).
[55] Baldochi S L, Courrol L C, Samad R E et al. Fluoride crystals growth and color center production by high intensity ultra short laser pulses[J]. Physica Status Solidi C, 4, 1060-1065(2007).
[56] Lonzaga J B, Avanesyan S M, Langford S C et al. Color center formation in soda-lime glass with femtosecond laser pulses[J]. Journal of Applied Physics, 94, 4332-4340(2003).
[57] Will M, Nolte S, Chichkov B N et al. Optical properties of waveguides fabricated in fused silica by femtosecond laser pulses[J]. Applied Optics, 41, 4360-4364(2002).
[58] Schaffer C B, García J F, Mazur E. Bulk heating of transparent materials using a high-repetition-rate femtosecond laser[J]. Applied Physics A, 76, 351-354(2003).
[59] Dekker P, Ams M, Marshall G D et al. Annealing dynamics of waveguide Bragg gratings: evidence of femtosecond laser induced colour centres[J]. Optics Express, 18, 3274-3283(2010).
[60] Burghoff J, Grebing C, Nolte S et al. Efficient frequency doubling in femtosecond laser-written waveguides in lithium niobate[J]. Applied Physics Letters, 89, 081108(2006).
[61] Burghoff J, Hartung H, Nolte S et al. Structural properties of femtosecond laser-induced modifications in LiNbO3[J]. Applied Physics A, 86, 165-170(2007).
[62] Burghoff J, Nolte S, Tünnermann A. Origins of waveguiding in femtosecond laser-structured LiNbO3[J]. Applied Physics A, 89, 127-132(2007).
[63] Luo F F, Qian B, Lin G et al. Redistribution of elements in glass induced by a high-repetition-rate femtosecond laser[J]. Optics Express, 18, 6262-6269(2010).
[64] Liu Y, Shimizu M, Zhu B et al. Micromodification of element distribution in glass using femtosecond laser irradiation[J]. Optics Letters, 34, 136-138(2009).
[65] Liu Y, Zhu B, Wang L et al. Femtosecond laser induced coordination transformation and migration of ions in sodium borate glasses[J]. Applied Physics Letters, 92, 121113(2008).
[66] Kanehira S, Miura K, Hirao K. Ion exchange in glass using femtosecond laser irradiation[J]. Applied Physics Letters, 93, 023112(2008).
[67] Sakakura M, Shimizu M, Shimotsuma Y et al. Temperature distribution and modification mechanism inside glass with heat accumulation during 250 kHz irradiation of femtosecond laser pulses[J]. Applied Physics Letters, 93, 231112(2008).
[68] Shimizu M, Sakakura M, Kanehira S et al. Formation mechanism of element distribution in glass under femtosecond laser irradiation[J]. Optics Letters, 36, 2161-2163(2011).
[69] Gorelik T, Will M, Nolte S et al. Transmission electron microscopy studies of femtosecond laser induced modifications in quartz[J]. Applied Physics A, 76, 309-311(2003).
[70] Osellame R, Lobino M, Chiodo N et al. Femtosecond laser writing of waveguides in periodically poled lithium niobate preserving the nonlinear coefficient[J]. Applied Physics Letters, 90, 241107(2007).
[71] Zhang H B, Eaton S M, Herman P R. Low-loss Type II waveguide writing in fused silica with single picosecond laser pulses[J]. Optics Express, 14, 4826-4834(2006).
[72] Nejadmalayeri A H, Herman P R. Ultrafast laser waveguide writing: lithium niobate and the role of circular polarization and picosecond pulse width[J]. Optics Letters, 31, 2987-2989(2006).
[73] Ramsay E, Thomson R R, Psaila N D et al. Laser action from an ultrafast laser inscribed Nd-doped silicate glass waveguide[J]. IEEE Photonics Technology Letters, 22, 742-744(2010).
[74] Pätzold W M, Demircan A, Morgner U. Low-loss curved waveguides in polymers written with a femtosecond laser[J]. Optics Express, 25, 263-270(2017).
[75] Pätzold W M, Reinhardt C, Demircan A et al. Cascaded-focus laser writing of low-loss waveguides in polymers[J]. Optics Letters, 41, 1269-1272(2016).
[76] Gui L, Xu B X, Chong T C. Microstructure in lithium niobate by use of focused femtosecond laser pulses[J]. IEEE Photonics Technology Letters, 16, 1337-1339(2004).
[77] Bookey H T, Thomson R R, Psaila N D et al. Femtosecond laser inscription of low insertion loss waveguides in Z-cut lithium niobate[J]. IEEE Photonics Technology Letters, 19, 892-894(2007).
[78] MacDonald J R, Thomson R R, Beecher S J et al. Ultrafast laser inscription of near-infrared waveguides in polycrystalline ZnSe[J]. Optics Letters, 35, 4036-4038(2010).
[79] Rodenas A, Kar A K. High-contrast step-index waveguides in borate nonlinear laser crystals by 3D laser writing[J]. Optics Express, 19, 17820-17833(2011).
[80] Chan J W, Huser T R, Risbud S H et al. Waveguide fabrication in phosphate glasses using femtosecond laser pulses[J]. Applied Physics Letters, 82, 2371-2373(2003).
[81] Osellame R, Chiodo N, Maselli V et al. Optical properties of waveguides written by a 26 MHz stretched cavity Ti: sapphire femtosecond oscillator[J]. Optics Express, 13, 612-620(2005).
[82] Stoian R, Cheng G, Mauclair C et al. 3D adaptive spatio-temporal control of laser-induced refractive index changes in optical glasses[J]. Proceedings of SPIE, 7921, 79210H(2011).
[83] Dharmadhikari J A, Dharmadhikari A K, Bhatnagar A et al. Writing low-loss waveguides in borosilicate (BK7) glass with a low-repetition-rate femtosecond laser[J]. Optics Communications, 284, 630-634(2011).
[84] Juodkazis S, Nishimura K, Tanaka S et al. Laser-induced microexplosion confined in the bulk of a sapphire crystal: evidence of multimegabar pressures[J]. Physical Review Letters, 96, 166101(2006).
[85] Mermillod-Blondin A, Bonse J, Rosenfeld A et al. Dynamics of femtosecond laser induced voidlike structures in fused silica[J]. Applied Physics Letters, 94, 041911(2009).
[86] Mishchik K, Cheng G, Huo G et al. Nanosize structural modifications with polarization functions in ultrafast laser irradiated bulk fused silica[J]. Optics Express, 18, 24809-24824(2010).
[87] Bain F M, Silva W F, Lagatsky A A et al. Microspectroscopy of ultrafast laser inscribed channel waveguides in Yb: tungstate crystals[J]. Applied Physics Letters, 98, 141108(2011).
[88] McMillen B, Chen K P, An H L et al. Waveguiding and nonlinear optical properties of three-dimensional waveguides in LiTaO3 written by high-repetition rate ultrafast laser[J]. Applied Physics Letters, 93, 111106(2008).
[89] Stuart B C, Feit M D, Rubenchik A M et al. Laser-induced damage in dielectrics with nanosecond to subpicosecond pulses[J]. Physical Review Letters, 74, 2248-2251(1995).
[90] Maruo S, Fourkas J T. Recent progress in multiphoton microfabrication[J]. Laser & Photonics Review, 2, 100-111(2008).
[91] Cao Y Y, Gan Z S, Jia B H et al. High-photosensitive resin for super-resolution direct-laser-writing based on photoinhibited polymerization[J]. Optics Express, 19, 19486-19494(2011).
[92] Liu S F, Hou Z W, Lin L H et al. 3D nanoprinting of semiconductor quantum dots by photoexcitation-induced chemical bonding[J]. Science, 377, 1112-1116(2022).
[93] Sanders S N, Schloemer T H, Gangishetty M K et al. Triplet fusion upconversion nanocapsules for volumetric 3D printing[J]. Nature, 604, 474-478(2022).
[94] Li L J, Gattass R R, Gershgoren E et al. Achieving λ/20 resolution by one-color initiation and deactivation of polymerization[J]. Science, 324, 910-913(2009).
[95] Han F, Gu S Y, Klimas A et al. Three-dimensional nanofabrication via ultrafast laser patterning and kinetically regulated material assembly[J]. Science, 378, 1325-1331(2022).
[96] Panusa G, Dinc N U, Psaltis D. Photonic waveguide bundles using 3D laser writing and deep neural network image reconstruction[J]. Optics Express, 30, 2564-2577(2022).
[97] Gašo P, Pudiš D A, Seyringer D et al. 3D polymer based 1x4 beam splitter[J]. Journal of Lightwave Technology, 39, 154-161(2021).
[98] Ocier C R, Richards C A, Bacon-Brown D A et al. Direct laser writing of volumetric gradient index lenses and waveguides[J]. Light: Science & Applications, 9, 196(2020).
[99] Porte X, Dinc N U, Moughames J et al. Direct (3+1)D laser writing of graded-index optical elements[J]. Optica, 8, 1281-1287(2021).
[100] Woods R, Feldbacher S, Zidar D et al. 3D optical waveguides produced by two photon photopolymerisation of a flexible silanol terminated polysiloxane containing acrylate functional groups[J]. Optical Materials Express, 4, 486-498(2014).
[101] Infuehr R, Pucher N, Heller C et al. Functional polymers by two-photon 3D lithography[J]. Applied Surface Science, 254, 836-840(2007).
