Extreme miniaturization of infrared spectrometers is critical for their integration into next-generation consumer electronics, wearables and ultrasmall satellites. In the infrared, there a necessary compromise between high spectral bandwidth resolution when miniaturizing dispersive elements, narrow band-pass filters reconstructive spectrometers. Fourier-transform are known large in infrared; however, they have not been fully miniaturized. Waveguide-based offer low device footprint, but rely...

We report on the operation of passively Q-switched waveguide lasers at 1 μm wavelength based a graphene∕WS 2 heterostructure as saturable absorber (SA).The gain medium is crystalline Nd:YVO 4 cladding produced by femtosecond laser writing.The nanosecond 1064 nm has been realized with maximum average output power 275 mW and slope efficiency 37%.In comparison systems single WS or graphene SA, lasing SA possesses advantages higher pulse energy enhanced efficiency, indicating promising...

Dielectric waveguides are widely recognized as excellent and versatile components for integrated multifunctional photonic chips, thanks to their strong optical confinement capabilities. In this study, we present a novel semi-tapered depressed-cladding waveguide structure, designed fabricated using femtosecond laser direct writing technology. The guiding performance of is systematically analyzed by characterizing its loss characteristics. Leveraging the high gain superior platform,...

Low-loss depressed cladding waveguide architecture is highly attractive for improving the laser performance of lasers. We report on design and fabrication “ear-like” structures formed by a set parallel tracks in neodymium-doped yttrium aluminum garnet (Nd:YAG) crystal via femtosecond writing. The obtained waveguides are with more symmetric mode profiles lower losses systematically comparing guiding properties two kinds normal waveguide. Efficient lasers realized based designed structure both...

We report on the fabrication of three-dimensional waveguide beam splitters in a dielectric Bi(4)Ge(3)O(12) (BGO) crystal by direct femtosecond laser writing. In written tracks BGO crystal, positive refractive index is induced, resulting so-called Type I configuration waveguiding cores. The "multiscan" technique utilized to shape cores with designed cross-sectional geometry order achieve guidance at mid-infrared wavelength 4 μm. fundamental mode along both TE and TM polarizations has been...

Low-loss depressed cladding waveguides have been produced in Nd:YAP laser crystal by using direct femtosecond writing. Under optical pump at 812 nm room temperature, continuous-wave simultaneous dual-wavelength oscillations 1064 and 1079 nm, both along TM polarization, realized the waveguiding structures. It has found that, with variation of intensity ratio emissions varies periodically, while polarization output remains unchanged. The maximum power achieved for waveguide lasers is ∼200 mW a...

We report on Q-switched waveguide lasers the graphene-based crystalline Y-branch platform. By applying direct femtosecond laser writing of Nd:YAG crystal, a surface splitter with geometry has been fabricated depressed cladding configuration. The lasing operation at 1064 nm is achieved in transmission mode, by attaching two-layer graphene resonator output mirror, as well using interaction between evanescent field and few-layer that was positioned right above Y-type waveguide. maximum average...

The femtosecond laser micromachining of transparent optical materials offers a powerful and feasible solution to fabricate versatile photonic components towards diverse applications. In this work, we report on new design fabrication ridge waveguides in LiNbO

We report on the fabrication of a nonlinear cladding waveguide in BiB3O6 crystal by using femtosecond laser inscription. The (with nearly circular cross section 150 µm diameter) shows good guiding properties two transverse polarizations. guided-wave second-harmonic generation (SHG) at 532 nm green light has been realized under CW and pulsed wave pump 1064 nm, based Type I birefringent phase matching configuration. conversion efficiencies for SHG are 0.083 25%, respectively.

We demonstrate multi-gigahertz continuous-wave mode-locking of a Yb:KLuW waveguide laser. A femtosecond-laser-inscribed channel in an extended laser cavity delivers fundamentally mode-locked near 1030 nm. tunable few-centimeter-long containing single-walled carbon nanotube saturable absorber as mode-locker generates self-starting femtosecond pulses with average output powers exceeding 210 mW at repetition rates 2.27, 2.69, and 3.55 GHz. The cavity, which includes wedged waveguide, is by...

Depressed-cladding surface channel waveguides were inscribed in a 0.5 at.% Pr:LiYF4 crystal by femtosecond Direct Laser Writing. The consisted of half-ring cladding (inner diameter: 17 µm) and side structures ("ears") improving the mode confinement. waveguide propagation loss was as low 0.14 ± 0.05 dB/cm. orange laser operating fundamental delivered 274 mW at 604.3 nm with 28.4% slope efficiency, threshold only 29 linear polarization (π), representing record-high performance for Pr lasers.

Two laser cleaning approaches based on ablation by ultraviolet pulses of femtosecond (fs) and nanosecond (ns) durations for the removal shellac varnish from egg-yolk tempera paints are investigated. Laser irradiation effects, induced layer underlying temperas multiple in fs domain at 398 265 nm single ns 213 nm, were examined following a spectroanalytical approach. By using optical microscopy, colorimetry fluorescence it was found that varnished with changes texture surface results...

We propose the use of kinoform diffractive lenses to focus near infrared femtosecond pulses in sapphire crystals for supercontinuum generation.It is shown that a strongly peaked structure appears blue region spectra.The central wavelength this peak can be easily controlled by simply changing lens-crystal distance.Moreover, when compared with generated refractive lens analogous conditions, spectral extension sogenerated continuum larger.Our results were corroborated plates different...

We report on the direct low-repetition rate femtosecond pulse laser microfabrication of optical waveguides in KTP crystals and characterization refractive index changes after thermal annealing sample, with focus studying potential for fabricating Mach-Zehnder modulators. have fabricated square cladding by means stacking damage tracks, found that decrease is large vertically polarized light (c-axis; TM polarized) but rather weak horizontally (a-axis; TE polarized), this leading to good...

Surface channel waveguides (WGs) were fabricated in a monoclinic Tm 3 :KLuWO 4 2 crystal by femtosecond direct laser writing (fs-DLW).The WGs consisted of half-ring cladding with diameters 50 and 60 μm located just beneath the surface.They characterized confocal microscopy μ-Raman spectroscopy, indicating reduced crystallinity stress-induced birefringence WG cladding.In continuous-wave (CW) mode, under Ti:sapphire pumping at 802 nm, maximum output power reached 171.1 mW 1847.4 corresponding...

We report on the design and fabrication of straight S-curved waveguides in neodymium-doped yttrium aluminate (Nd:YAP) crystal by using direct femtosecond laser writing. These channel are based hexagonal optical-lattice-like depressed cladding geometry. For each type waveguide, S-curves with three lateral offsets 50 μm, 100 150 μm implemented. good guiding properties low bending losses. With waveguide as cavity, dual-wavelength, 31.6 GHz operating at 1064 nm 1079 have been demonstrated MoS2 a...

In this work we apply second harmonic microscopy to the analysis of damage tracks inscribed by femtosecond laser irradiation in a Nd:YAG crystal. While generation is not expected bulk centrosymmetric material, 2D and 3D images obtained via show that induced micro-modification crystal structure leads localized nonlinear signal. The nature modification its dependence on detection parameters discussed. These findings demonstrate capability for morphological written structures open door design...

We report on the fabrication of ridge waveguides and Y-branch beam splitters in KTiOAsO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sub> nonlinear optical crystal by combination 15 MeV oxygen (O <sup xmlns:xlink="http://www.w3.org/1999/xlink">5+</sup> ) ion implantation femtosecond laser ablation. Guiding properties were investigated at wavelengths 633 808 nm, respectively, showing high polarization sensitivity light propagation....

We report on efficient laser operation of the first holmium monoclinic double tungstate waveguide fabricated by femtosecond direct writing. A depressed-index buried channel with a 60 μm diameter circular cladding was inscribed in 5 at.% Ho3+:KGd(WO4)2. It characterized confocal microscopy and μ-Raman μ-luminescence spectroscopy, indicating well-preserved crystallinity its core. Pumped thulium bulk laser, generated 212 mW at 2055 nm slope efficiency 67.2%. The propagation losses were 0.94±0.2 dB/cm.

We report on the fabrication of ring-shaped waveguides operating at telecommunication band in a cubic Bi4Ge3O12 (BGO) crystal by using technique femtosecond laser writing. In regions written tracks BGO crystal, positive refractive index is induced, resulting so-called Type I configuration. The modal profiles are within designed track cladding with geometries, which analogous to circular optical lattices. homogenous guidance along both TE and TM polarizations has been obtained wavelength 1.55...

We report on the fabrication of depressed cladding waveguides in periodically poled MgO doped LiTaO3 by using low-repetition-rate femtosecond laser writing, and their use for guided-wave second harmonic generation (SHG). The exhibit different guiding performance along extraordinary ordinary polarizations. temperature-dependent quasi-phase-matching (QPM) is realized to obtain SHG waveguides. results show that QPM temperature was dependent poling period features highest nonlinear conversion...