Loading [MathJax]/extensions/MathMenu.js
Feng Chen - IEEE Xplore Author Profile

Showing 1-25 of 36 results

Filter Results

Show

Results

We report a micron-scale tailored waveguide-grating device designed for vortex laser generation in the Tm:YLF crystal inscribed by femtosecond laser direct writing (FLDW). The confocal micro-Raman measurement clarifies the microscopic mechanisms of the laser modification on the crystal lattice and the formation of the waveguide and the fork grating. The guiding performance and diffraction properti...Show More
Crystalline waveguides well combine the excellent optical confinement of waveguide structures and the rich optical properties of crystalline materials, rendering them promising candidates for waveguide devices and integrated photonic components. Femtosecond-laser-direct writing (FsLDW), as a true three-dimensional (3D) micromachining and microfabrication technology, allows rapid prototyping of on-...Show More
Implantation of He+ -ions is an attractive method of creating optical waveguides in LiNbO3. The advantages of this method are that, firstly, the main optical characteristics of He - implanted waveguides (denoted below as He-LiNbO3) are identical to those of the bulk LiNbO3, and, secondly, a He-implanted layer provides an abrupt boundary of the waveguide. We describe the AFM-tip domain writing in p...Show More
We report on a novel waveguide-based polarization beam splitter (PBS) fabricated by femtosecond (fs) laser in lithium niobate (LiNbO3) crystals. This monolithic PBS is composed of tailored waveguide configurations with different guiding properties in which linearly polarized light along extraordinary refractive index (ne) and ordinary index (no) can be well separated. At the wavelength of 1064 nm,...Show More
We report on the design and fabrication of straight and S-curved waveguides in neodymium-doped yttrium aluminate (Nd:YAP) crystal by using direct femtosecond laser writing. These S-curved channel waveguides are based on the hexagonal optical-lattice-like and depressed cladding geometry. For each type waveguide, S-curves with three lateral offsets of 50 μm, 100 μm, and 150 μm are implemented. These...Show More
Waveguide arrays are basic photonic elements in integrated optics. We propose a 3D hybrid-integrated waveguide array based on the femtosecond laser writing of lithium niobate (LiNbO3) crystals by engineering the layout of laser-induced tracks. The cross section of the structure is a cross-shaped geometry. The light propagation through this waveguide array shows polarization-dependent behaviors, wh...Show More
Waveguides are light wave guiding microstructures that play important roles in the field of integrated optics. Femtosecond laser writing is a promising way to fabricate these microscale waveguides according to the demands in practical applications. In recent years, waveguide lasers have been recognized as compact and miniature laser sources that could be on-chip integrated within photonics circuit...Show More
We report on a one-step fabrication method of horizontal dual-line waveguides supporting TE guidance in LiTaO3 crystal utilizing multiple refocusing mechanisms of the femtosecond laser. Through the nonlinear process, multiple foci can be formed spontaneously with the interval of a few micrometers along the laser propagation direction. The number and the separation of focal spots, even the entire l...Show More
Channel waveguide in Pr:YLF crystal is fabricated by femtosecond laser (fs-laser) micromachining system. The micro Raman (μ-Raman) spectra and scanning confocal fluorescence imaging investigations of the depressed cladding structure indicated that slight changes (with respect to widths of the emission lines and spectral positions) have been generated in the laser-modification region. The microphot...Show More
We report on the direct fabrication of type I and type II waveguides in z-cut lithium tantalate crystal by varying the parameters of femtosecond laser. The waveguiding properties and reflectance spectrum of the fabricated waveguides were also characterized in this work.Show More
We report on the fabrication of three-dimensional (3D) waveguide coupler in lithium niobate crystal by using femtosecond laser writing based on laser-induced extraordinary index changes of Type I modification. This coupler is used to implement 1×4 beam splitting at 632.8 nm. The numerical simulations of beam evolution are in agreement with the experimental results.Show More
We report on the fabrication of waveguide arrays based on depressed-cladding structures produced by femtosecond laser direct inscription in a Nd:YAG crystal. The arrays consisted of seven divergent hexagonal waveguides with different separations between the waveguides at the exit of the crystal. Optical characterization in the visible (633 nm) and near infrared (800 nm) was performed. The obtained...Show More
In this study, mechanically defined ridge waveguides were fabricated based on a planar periodically poled LiNbO3 waveguide formed by swift carbon ion irradiation. The second harmonic generation within the telecommunication band was demonstrated in these ridges. A normalized conversion efficiency as high as 77.9%/(W · cm2) was realized. The effect of the thermal annealing process on the quasi-phase...Show More
We report on the fabrication of ridge waveguides and Y-branch beam splitters in KTiOAsO4 nonlinear optical crystal by the combination of 15 MeV oxygen (O5+) ion implantation and femtosecond laser ablation. Guiding properties were investigated at the wavelengths of 633 and 808 nm, respectively, showing high polarization sensitivity of light propagation. Splitting ratios of these beam splitters are ...Show More
We report on the continuous-wave and passively Q-switched waveguide laser at the wavelength of ~1024 nm, based on the (Yb0.1Y0.9)3(Sc1.5Ga0.5)Ga3O12 (Yb:YSGG) crystal. The ridged waveguide was fabricated on the surface of 100 at% Yb:YSGG crystal by the swift ion irradiation and the precise diamond blade dicing. Utilizing this waveguide as the gain medium and resonant cavity, the laser emission at ...Show More
Miniature light sources are desirable for integrated photonic devices. Dielectric crystals with diverse structures and functions are important media for various photonic and optical applications. Laser crystals serve as gain media for solid state laser systems, which have been applied for generation of wavelength bands from visible till mid-infrared. Direct processing of dielectric crystals by “ph...Show More
We report on the fabrication of optical ridge waveguides in Yb:YCOB crystal. The ridge waveguide structures show good guiding properties at 1064 nm along TM polarization and the lowest propagation loss is measured to be 1.7 dB/cm.Show More
The waveguide beam splitters with diverse configurations in LiNbO3 crystal have been produced by direct femtosecond laser writing of a family of optical-lattice-like cladding structures. By on demand design of the lattice tracks with “defect” lines, the efficient beam guiding and tailoring have been implemented in the structures. With a family of three-element integration of structures, three-dime...Show More
In this paper, we report on a three-dimensional beam splitter monolithically integrated in an Nd:YAG laser crystal wafer by applying the direct femtosecond laser writing technique with the photonic-lattice-like cladding approach, capable of 1 to 2 and 1 to 4 beam splitting. Using the pump at 808 nm, 1064-nm splitting lasers with slope efficiencies of 34% and 22% for 1 to 2 and 1 to 4 configuration...Show More
Rectangular Y-branch cladding waveguides have been fabricated in Nd:YAG crystal by femtosecond laser inscription. Such novel configurations are fabricated with depth of 50 μm, supporting multimode guidance in both TM and TE polarizations. Continuous wave laser oscillations at wavelength of 1.06 μm have been achieved under the optical pump at 808 nm. The maximum output power is 0.2 W with a slope e...Show More
We present the results of studies in planar optical waveguides fabricated by He-ion implantation with the energy of 500 keV in X-cut LiNbO3 crystals. The thickness of the formed waveguide layer confined by the depth D of the implanted layer is of about 1.06 μm. The refractive indices as well as differences in refractive indices were evaluated for wavelengths λ = 445, 626.5, and 650 nm. Domain grat...Show More
We report a pulsed waveguide laser working at 1944 nm, mode-locked with a saturable absorber consisting of a graphene film deposited on an output coupler mirror. The waveguide is created into a ceramic Thulium-doped Yttrium Aluminium Garnet by ultrafast laser inscription. Q-switched mode-locking is achieved, with 6.5 mW average output power and ∼7.8 GHz pulse rate. This is a convenient, compact, h...Show More
This paper reports on the quasi-three-level continuous wave laser operation based on waveguide structures in neodymium-doped calcium niobium gallium garnet disordered crystal. Laser wavelength selection through the waveguide cross section was observed. Waveguide structures with different cross sections were fabricated by the ultrafast laser inscription, which have propagation losses around 1 dB/cm...Show More
We report on proton beam writing of chalcogenide glass for the fabrication of channel waveguides. The focused proton beam at an energy of 1 MeV induces positive refractive index changes, forming channel waveguide structures in the irradiated region. The channel waveguides support both the TE and TM polarizations from the visible to near-infrared telecommunication O and C bands. Based on the maximu...Show More