Birefringence; Bragg grating; Femtosecond laser; Fused silica; Refractive index; Waveguide; Atomic and Molecular Physics, and Optics
Abstract :
[en] Since their advent, femtosecond (fs) laser pulses have been effectively employed to create micro and nano structures within host materials, such as silica glass. Their application is of growing interest in the fields of photonics and optomechanics and numerous achievements have been obtained to date. The technology has matured to such a degree that automated production processes like the FemtoPrint machine are now commercially available. While dealing with such powerful tools, users need to optimize the energy per pulse and polarization state to create effective structures on purpose. Thereby, studying the effect of these parameters on the relative quality of the fs laser pulses-engineered structures is of prime importance and can bring assistance or even a useful methodology for the scientific community using this tool or an equivalent technique. In this study, our focus revolves around exploring the characteristics of optical waveguides and in-built Bragg gratings created with the Femtoprint process in a flat glass substrate to extract pertinent information regarding their physical and optical properties, such as dimensions, refractive index modulation and birefringence. To that aim, we rely on three advanced methodologies: Digital holographic Microscope (DHM) analysis, polarization-based spectral measurements and infrared camera imaging, respectively. This analysis reveals important findings about the actual implemented refractive index modulation. For the investigated pulse energy (130 nJ), repetition rate (1 MHz) and scanning speed of the fs laser pulses beam, we show that the refractive index modification in the waveguide determined by DHM analysis lies in the range of 10-3. This value is the highest reported so far in waveguides at this relatively low energy and high repetition rate of the laser pulses. Besides, the Bragg grating inscribed in the waveguide shows a spectral separation between the Bragg modes (300 pm) corresponding to an effective birefringence of the waveguide of 1.36 10-4. This value depends on the polarization of the writing beam with respect to the scanning direction.
Disciplines :
Materials science & engineering
Author, co-author :
de Lara, M.Tunon; Electromagnetism and Telecommunication Department, Université de Mons, Belgium ; TIPs Department, CP 165/67, Université Libre de Bruxelles, Brussels, Belgium
Droz, L.Amez; TIPs Department, CP 165/67, Université Libre de Bruxelles, Brussels, Belgium ; Department of Aerospace and Mechanical Engineering, Université de Liège, Liège, Belgium
Chah, K.; Electromagnetism and Telecommunication Department, Université de Mons, Belgium
Lambert, P. ; TIPs Department, CP 165/67, Université Libre de Bruxelles, Brussels, Belgium
Collette, C. ; Department of Aerospace and Mechanical Engineering, Université de Liège, Liège, Belgium ; BEAMS Department, CP 165/56, Université Libre de Bruxelles, Brussel, Belgium
Caucheteur, Christophe ; Université de Mons - UMONS > Faculté Polytechnique > Service d'Electromagnétisme et Télécommunications
Language :
English
Title :
Characterization of birefringent Bragg gratings waveguides inscribed with the Femtoprint device
Amez-droz, L., De Lara, M.T., Collette, C., Caucheteur, C., Lambert, P., Instrumented Flexible Glass Structure: A Bragg Grating Inscribed with Femtosecond Laser Used as a Bending Sensor. Sensors, 23(19), 2023, 8018, 10.3390/s23198018.
Ams, M., Marshall, G.D., Withford, M.J., Study of the influence of femtosecond laser polarisation on direct writing of waveguides. Opt. Express., 14, 2006, 13158, 10.1364/oe.14.013158.
Bellouard, Y., On the bending strength of fused silica flexures fabricated by ultrafast lasers. Opt. Mater. Express., 1, 2011, 816, 10.1364/ome.1.000816.
Bellouard, Y., Said, A., Dugan, M., Bado, P., Fabrication of high-aspect ratio, micro-fluidic channels and tunnels using femtosecond laser pulses and chemical etching. Opt. Express., 12, 2004, 2120, 10.1364/opex.12.002120.
Beresna, M., Gecevičius, M., Kazansky, P.G., Ultrafast laser direct writing and nanostructuring in transparent materials. Adv. Opt. Photonics., 6, 2014, 293, 10.1364/aop.6.000293.
Canning, J., Lancry, M., Cook, K., Weickman, A., Brisset, F., Poumellec, B., Anatomy of a Femtosecond Laser Processed Silica Waveguide 1 (2011), 998–1008.
Casamenti, E., Pollonghini, S., Bellouard, Y., Few pulses femtosecond laser exposure for high efficiency 3D glass micromachining. Opt. Express., 29, 2021, 35054, 10.1364/oe.435163.
Caucheteur, C., Bette, S., Garcia-Olcina, R., Wuilpart, M., Sales, S., Capmany, J., Mégret, P., Transverse strain measurements using the birefringence effect in fiber Bragg gratings. IEEE Photonics Technol. Lett. 19 (2007), 966–968, 10.1109/LPT.2007.897566.
Chah, K., Kinet, D., Wuilpart, M., Mégret, P., Caucheteur, C., Femtosecond-laser-induced highly birefringent Bragg gratings in standard optical fiber. Opt. Lett., 38, 2013, 594, 10.1364/ol.38.000594.
Chan, J.W., Huser, T., Risbud, S., Krol, D.M., Structural changes in fused silica after exposure to focused femtosecond laser pulses. Opt. Lett., 26, 2001, 1726, 10.1364/ol.26.001726.
Eaton, S.M., Zhang, H., Ng, M.L., Li, J., Chen, W.J., Ho, S., Herman, P.R., Transition from thermal diffusion to heat accumulation in high repetition rate femtosecond laser writing of buried optical waveguides. Opt. Express 16 (2008), 9443–9458, 10.1364/OE.16.009443.
Gattass, R.R., Rafael, R., Mazur, E., Femtosecond laser micromachining in transparent materials. Nat. Photonics 2:4 (2008), 219–225, 10.1038/nphoton.2008.47.
Hnatovsky, C., Taylor, R.S., Rajeev, P.P., Simova, E., Bhardwaj, V.R., Rayner, D.M., Corkum, P.B., Pulse duration dependence of femtosecond-laser-fabricated nanogratings in fused silica. Appl. Phys. Lett., 87, 2005, 10.1063/1.1991991.
Joglekar, A.P., Liu, H., Spooner, G.J., Meyhöfer, E., Mourou, G., Hunt, A.J., A study of the deterministic character of optical damage by femtosecond laser pulses and applications to nanomachining. Appl. Phys. B Lasers Opt. 77 (2003), 25–30, 10.1007/s00340-003-1246-z.
Kiyama, S., Matsuo, S., Hashimoto, S., Morihira, Y., Examination of etching agent and etching mechanism on femotosecond laser microfabrication of channels inside vitreous silica substrates. J. Phys. Chem. c. 113 (2009), 11560–11566, 10.1021/jp900915r.
Li, L., Kong, W., Chen, F., Femtosecond laser-inscribed optical waveguides in dielectric crystals: a concise review and recent advances. Advanced Photonics, 4, 2022, 2, 10.1117/1.AP.4.2.024002.
Little, D.J., Ams, M., Dekker, P., Marshall, G.D., Dawes, J.M., Withford, M.J., Femtosecond laser modification of fused silica: the effect of writing polarization on Si-O ring structure. Opt. Express 16 (2008), 20029–20037, 10.1364/OE.16.020029.
Liu, X., Du, D., Mourou, G., Laser ablation and micromachining with ultrashort laser pulses. IEEE J. Quantum Electron. 33 (1997), 1706–1716, 10.1109/3.631270.
Malinauskas, M., Žukauskas, A., Hasegawa, S., Hayasaki, Y., Mizeikis, V., Buividas, R., Juodkazis, S., Ultrafast laser processing of materials: From science to industry. Light Sci. Appl. 5 (2016), 3–5, 10.1038/lsa.2016.133.
Marcinkevičius, A., Juodkazis, S., Watanabe, M., Miwa, M., Matsuo, S., Misawa, H., Nishii, J., Femtosecond laser-assisted three-dimensional microfabrication in silica. Opt. Lett., 26, 2001, 277, 10.1364/ol.26.000277.
Pasaila, N.D., Thomson, R.R., Bookey, H.T., Kar, A.K., Chiodo, N., Osellame, R., Cerullo, G., Brown, G., Jha, A., Shen, S., Femtosecond laser inscription of optical waveguides in Busmuth ion doped glass. Opt. Express. 14:22 (2006), 10452–10459.
Tan, D., Sharafudeen, K.N., Yue, Y., Qiu, J., Femtosecond laser induced phenomena in transparent solid materials: Fundamentals and applications. Prog. Mater Sci. 76 (2016), 154–228, 10.1016/j.pmatsci.2015.09.002.
Taylor, R.S., Hnatovsky, C., Simova, E., Rayner, D.M., Bhardwaj, V.R., Corkum, P.B., Ultra-high resolution index of refraction profiles of femtosecond laser modified silica structures. OSA Trends Opt. Photonics Ser. 88 (2003), 1248–1249, 10.1364/oe.11.000775.
Taylor, R.S., Hnatovsky, C., Simova, E., Rayner, D.M., Bhardwaj, V.R., Corkum, P.B., Femtosecond laser fabricated nanostructures in silica glass. OSA Trends Opt. Photonics Ser. 88 (2003), 1009–1010, 10.1364/ol.28.001043.
Tien, A.C., Backus, S., Kapteyn, H., Murnane, M., Mourou, G., Short-pulse laser damage in transparent materials as a function of pulse duration. PhysRevLett. 82 (1999), 3883–3886, 10.1103/PhysRevLett.82.3883.
Tunon de Lara, M., Chah, K., Amez-Droz, L., Lambert, P., Collette, C., Caucheteur, C., Production of an optical waveguide in planar glass substrate fabricated with femtoprint. Proc. SPIE, 2022, International Society for Optical Engineering, Bellingham, USA.
Tunon de Lara, M., Amez-Droz, L., Chah, K., Lambert, P., Collette, C., Caucheteur, C., Femtosecond pulse laser-engineered glass flexible structures instrumented with an in-built Bragg grating sensor. Opt. Express., 31, 2023, 29730, 10.1364/oe.497482.
Zhou, K., Dubov, M., Mou, C., Zhang, L., Mezentsev, V.K., Bennion, I., Line-by-line fiber bragg grating made by femtosecond laser. IEEE Photonics Technol. Lett. 22 (2010), 1190–1192, 10.1109/LPT.2010.2050877.
