Nicholas D. Psaila

Ultrafast-laser inscription of a three dimensional fan-out device for multicore fiber coupling applications

A three dimensional fan-out device has been fabricated using ultrafast laser inscription. The device allows each core of a multicore fibre to be addressed individually by a single mode fiber held in an FVA.

Three-dimensional mid-infrared photonic circuits in chalcogenide glass

We report the fabrication of single-mode buried channel waveguides for the whole mid-IR transparency range of chalcogenide sulphide glasses (λ ≤ 11 μm), by means of direct laser writing. We have explored the potential of this technology by fabricating a prototype three-dimensional three-beam combiner for future application in stellar interferometry that delivers a monochromatic interference visibility of 99.89% at 10.6 μm and an ultrahigh bandwidth (3-11 μm) interference visibility of 21.3%. These results demonstrate that it is possible to harness the whole transparency range offered by chalcogenide glasses on a single on-chip instrument by means of direct laser writing, a finding that may be of key significance in future technologies such as astrophotonics and biochemical sensing.

Ultrafast laser inscribed Yb:KGd(WO4)2 and Yb:KY(WO4)2 channel waveguide lasers.

We demonstrate laser action in diode-pumped microchip monolithic cavity channel waveguides of Yb:KGd(WO(4))(2) and Yb:KY(WO(4))(2) that were fabricated by ultrafast laser writing. The maximum output power achieved was 18.6 mW with a threshold of approximately 100 mW from an Yb:KGd(WO(4))(2) waveguide laser operating at 1023 nm. The propagation losses for this waveguide structure were measured to be 1.9 dBcm(-1).

Er:Yb-doped oxyfluoride silicate glass waveguide amplifier fabricated using femtosecond laser inscription

The authors report net gain from a channel waveguide fabricated in an Er:Yb-doped oxyfluoride silicate glass substrate using femtosecond laser waveguide inscription. To fabricate waveguides exhibiting low propagation and coupling losses, they used the recently demonstrated multiscan technique that allows the waveguide cross section and refractive index contrast to be controlled independently of each other. By doing so, the best waveguide exhibited a total background insertion loss, excluding absorption, of only 1.2dB at 1537nm. As a result, a fiber-fiber net gain of 0.72dB at 1537nm was measured for a 10mm long waveguide.The authors report net gain from a channel waveguide fabricated in an Er:Yb-doped oxyfluoride silicate glass substrate using femtosecond laser waveguide inscription. To fabricate waveguides exhibiting low propagation and coupling losses, they used the recently demonstrated multiscan technique that allows the waveguide cross section and refractive index contrast to be controlled independently of each other. By doing so, the best waveguide exhibited a total background insertion loss, excluding absorption, of only 1.2dB at 1537nm. As a result, a fiber-fiber net gain of 0.72dB at 1537nm was measured for a 10mm long waveguide.

Femtosecond laser writing of waveguides in periodically poled lithium niobate preserving the nonlinear coefficient

Optical waveguides have been inscribed in periodically poled lithium niobate by femtosecond laser pulses with the multiscan technique. Second harmonic generation experiments from a fundamental wavelength of 1567nm demonstrate that the nonlinear optical coefficient in the waveguides is preserved, yielding a conversion efficiency of 18%W−1.

Supercontinuum generation in an ultrafast laser inscribed chalcogenide glass waveguide.

We report on the fabrication and characterisation of waveguides fabricated in a GeS based chalcogenide glass. A wide range of waveguiding structures were fabricated, and supercontinuum generation was demonstrated for a highly multimode waveguide.

320 fs pulse generation from an ultrafast laser inscribed waveguide laser mode-locked by a nanotube saturable absorber

Ultrafast laser inscription is used to fabricate the gain element for a mode-locked Er-doped bismuthate glass waveguide laser. Mode-locking is initiated and stabilized by the use of a single wall carbon nanotube saturable absorber. The waveguide laser produces 320 fs pulses at 1.56 μm with a pulse repetition rate of 40 MHz and average output power of 1.25 mW.

Ultrafast laser inscription of near-infrared waveguides in polycrystalline ZnSe

We report the successful fabrication of a low-loss near-IR waveguide in polycrystalline ZnSe using ultrafast laser inscription. The waveguide, which was inscribed using the multiscan fabrication technique, supported a well-confined mode at 1.55 μm. Propagation losses were characterized at 1.55 μm using the Fabry-Perot technique and found to be 1.07 dB · cm(-1) ± 0.03 dB · cm(-1).

Femtosecond Laser Inscription of Low Insertion Loss Waveguides in

A low insertion loss waveguide is fabricated in z-cut lithium niobate using femtosecond laser waveguide inscription. To fabricate a waveguide exhibiting both low propagation and coupling losses, we used the multiscan fabrication technique to control the size of the waveguide cross section. A minimum insertion loss of only 3.5 dB at 1550 nm was measured for the 18-mm-long waveguide when directly coupled to Corning SMF-28 fibers. Of this 3.5dB, we attribute 2.1 dB to coupling losses, 1.1 dB to propagation losses, and 0.3 dB to Fresnel reflections

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We report on the fabrication of high quality embedded channel waveguides inside Bi-doped silicate glass using femtosecond waveguide inscription. Waveguides are fabricated using both single and multi-scan fabrication techniques. Refractive index modifications of up to ∆n = 4.3×10-3 are observed, allowing the fabrication of waveguides nearly mode-matched to telecom fibers. When optically pumped at 980 and 810 nm broadband fluorescence emission centered at 1.3 μm with a FWHM of up to 500 nm is detected.