Femtosecond laser written waveguides deep inside silicon


Pavlov I. , Tokel O., Pavlova S., Kadan V., Makey G., Turnali A., ...Daha Fazla

OPTICS LETTERS, cilt.42, ss.3028-3031, 2017 (SCI İndekslerine Giren Dergi) identifier identifier identifier

  • Cilt numarası: 42 Konu: 15
  • Basım Tarihi: 2017
  • Doi Numarası: 10.1364/ol.42.003028
  • Dergi Adı: OPTICS LETTERS
  • Sayfa Sayıları: ss.3028-3031

Özet

Photonic devices that can guide, transfer, or modulate light are highly desired in electronics and integrated silicon (Si) photonics. Here, we demonstrate for the first time, to the best of our knowledge, the creation of optical waveguides deep inside Si using femtosecond pulses at a central wavelength of 1.5 mu m. To this end, we use 350 fs long, 2 mu J pulses with a repetition rate of 250 kHz from an Er-doped fiber laser, which we focused inside Si to create permanent modifications of the crystal. The position of the beam is accurately controlled with pump-probe imaging during fabrication. Waveguides that were 5.5 mm in length and 20 mu m in diameter were created by scanning the focal position along the beam propagation axis. The fabricated waveguides were characterized with a continuous-wave laser operating at 1.5 mu m. The refractive index change inside the waveguide was measured with optical shadowgraphy, yielding a value of 6 x 10(-4), and by direct light coupling and far-field imaging, yielding a value of 3.5 x 10(-4). The formation mechanism of the modification is discussed. (C) 2017 Optical Society of America