To our knowledge, we report the first waveguide laser operation of Tm3+:BaY2F8 crystal near the wavelength of 2 mu m. Femtosecond laser inscription was employed to fabricate two waveguides, each in the form of a circu...
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To our knowledge, we report the first waveguide laser operation of Tm3+:BaY2F8 crystal near the wavelength of 2 mu m. Femtosecond laser inscription was employed to fabricate two waveguides, each in the form of a circular depressed cladding, with diameters of 30 mu m and 50 mu m. For the 50-mu m-diameter waveguide, the propagation loss was determined as 0.22 dB/cm at the wavelength of 731 nm. A two-mirror resonator consisting of a buttcoupled input high reflector and a 10-cm-radius curved output coupler housed the Tm3+:BaY2F8 crystal waveguide during lasing experiments. By using a continuous-wave Ti3+:sapphire laser at 781 nm, waveguide lasing was obtained at 1.86 mu m. By using a 6% output coupler, as high as 73 mW of output power was obtained with the 50-mu m-diameter waveguide at an incident pump power of 680 mW, corresponding to a slope efficiency of 13.1%. Lasing threshold pump powers as low as 23 mW were further achieved with a 2% output coupler by using the 30-mu m-diameter waveguide. These results show that the Tm3+:BaY2F8 crystal possesses an important potential in the development of compact, efficient, femtosecond laser written waveguide lasers near 2 mu m.
We report on two selective functionalization strategies to create a chemical contrast between the active rib waveguides and the passive surrounding areas of a chalcogenide-based optical sensing system. In such configu...
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We report on two selective functionalization strategies to create a chemical contrast between the active rib waveguides and the passive surrounding areas of a chalcogenide-based optical sensing system. In such configuration, the analyte could be concentrated on the waveguides and interact with the evanescent field, producing a stronger optical signature. The rib waveguides are obtained by photolithography and subsequent ion beam etching of amorphous Ge-Se-Te thin films that allow residual resist to remain above the waveguides. The first functionalization strategy consists in the reuse of the resist as a mask during the following surface modification process. It allows the functionalization of all areas around the waveguides. The second strategy consists of depositing a new sacrificial metal layer, leading to a perfect negative functionalization contrast, modifying only the waveguides. For the two strategies developed, three precursors were used. The use of a silylated fluorescein derivative allowed the validation of the protocols, with the observation of a fluorescence contrast between the functionalized and non-functionalized areas. The use of tetraethoxysilane as a hydrophilic precursor and the mixture of tetraethoxysilane and octyl-trimethoxysilane as a hydrophobic precursor created a clear contrast in wettability between the rib waveguides and the surrounding areas. A spore deposition was performed on functionalized components according to the two proposed strategies, with the two hydrophilic/hydrophobic precursors. The spore immobilization rate was increased by making the waveguides more hydrophobic, as well as by making the areas surrounding the guides more hydrophilic, demonstrating the effectiveness of our two strategies.
We study propagation dynamics of incoherently coupled two-frequency pulse compounds in waveguides with single zero-dispersion and zero-nonlinearity points. We demonstrate nonlinear-photonics meta-atoms and molecule-li...
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ISBN:
(纸本)9781957171258
We study propagation dynamics of incoherently coupled two-frequency pulse compounds in waveguides with single zero-dispersion and zero-nonlinearity points. We demonstrate nonlinear-photonics meta-atoms and molecule-like bound-states of pulses that persist in presence of the Raman effect.
We introduce a rigorous first-principles methodology to simultaneously couple multiple transverse spatial modes of multimode waveguides with arbitrary amplitudes/phases and show techniques to suppress undesired crosst...
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ISBN:
(纸本)9781957171258
We introduce a rigorous first-principles methodology to simultaneously couple multiple transverse spatial modes of multimode waveguides with arbitrary amplitudes/phases and show techniques to suppress undesired crosstalk arising from nonideal nonlinear effects by ~20 dB.
In solid quantum systems, strong phonon-phonon repulsive or attractive interactions are difficult to achieve. The highly adjustable phonon-phonon interactions created by silicon-vacancy (SiV) centers in a one-dimensio...
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In solid quantum systems, strong phonon-phonon repulsive or attractive interactions are difficult to achieve. The highly adjustable phonon-phonon interactions created by silicon-vacancy (SiV) centers in a one-dimensional chiral phononic waveguide are investigated in this paper. Under specific situations, phonon-phonon attractive or repulsive interactions between the chiral transport phonons are created when they are scattered by two-level or three-level structural SiV centers. Furthermore, by modulating the laser Rabi frequencies and detunings, the resultant attractive or repulsive interactions between phonons can be adjusted over a large frequency range. Single-phonon creation and phonon manipulation in solid acoustic quantum information processing could benefit from the tunable phonon-phonon interactions.
Silicon photonics (SiPh) and photonic integrated circuits (PIC) provide an increasingly important technology platform enabling the on-chip combination of photonics and electronics [1] while offering solutions for a wi...
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ISBN:
(纸本)9798350345995
Silicon photonics (SiPh) and photonic integrated circuits (PIC) provide an increasingly important technology platform enabling the on-chip combination of photonics and electronics [1] while offering solutions for a wide range of applications, such as high-capacity networks and sensing [2], for example. As the SiPh waveguides cannot provide gain, different integration schemes of III-V compound semiconductors gain chips are necessary to enable on-chip light generation. Hybrid integration is a solution where a diced II- V gain chip is bonded on a PIC platform [3]. This approach provides the freedom to combine a multitude of different types of III- V chips on a PIC and is also compatible with current CMOS industry as the fabrication of the III-V chip is separated from the PIC production. However, one of the challenges of hybrid integration, is the alignment of the gain chip on the PIC. For low-loss operation, sub-micron alignment precision should be reached. This, however, is in part limited by the accuracy of the current dicing systems resulting in poor dimension control and a requirement for larger alignment tolerances.
The heterogeneous integration of III-V semiconductors (III-Vs) with the Si platform allows to merge photon sources with Si electronics while enabling the use of micro-electro mechanical systems (MEMS) mature processin...
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ISBN:
(纸本)9798350345995
The heterogeneous integration of III-V semiconductors (III-Vs) with the Si platform allows to merge photon sources with Si electronics while enabling the use of micro-electro mechanical systems (MEMS) mature processing techniques. The inherent insufficient quality of III-Vs' native and thermal oxides make imperative the use of deposited interfacial oxide layers for bonding full wafers [1]. The traditional method of choice to overcome that problem is plasma-enhaced chemical vapor deposition due to its low deposition temperature, which prevents the dissociation of III-Vs [1]. Here, we present further developments on a novel technique [2], greatly enhancing its Si platform compatibility. As a result, the transfer of top cladded InGaP waveguides (WGs) to a standard Si wafer with wet-thermal oxide thickness of 4μm has been experimentally demonstrated. Consequently, double inverse-tapered WGs can be realized enhancing the in/out-coupling while offering unprecedented freedom in the target substrate design constrains due to the well-known Bosch Si etching process. The surface optical nonlinearity of the transferred WGs has been used for modal phase-matched second-harmonic generation (SHG) [3].
We present the sol-gel fabrication and characterization of SiO2-TiO2 one-dimensional photonic crystal (1DPhC) waveguides embedded with a low-index defect layer as the core. We demonstrate femtosecond laser micromachin...
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We present the sol-gel fabrication and characterization of SiO2-TiO2 one-dimensional photonic crystal (1DPhC) waveguides embedded with a low-index defect layer as the core. We demonstrate femtosecond laser micromachining as an attractive technique for microfabrication on multilayer structures over other conventional techniques like, electron beam lithography and focused ion beam milling. 1DPhC channel waveguides of widths 15.3 +/- 0.5 and 17.8 +/- 0.5 mu m were fabricated using optimised femtosecond laser micmmachining technique, and their waveguiding characteristics were studied in the end-fire coupling geometry. The modes in the fabricated structures exhibit confinement in the core, which creates an efficient way of light guiding via leaky modes for applications in optical integrated circuits. The waveguiding in the fabricated 1DPhC channel waveguides are attributed to light confinement due to the photonic stop-band in the out-of-plane direction and total internal reflection in the in-plane direction. Polarization dependent studies show that the modes supported by the 1DPhC planar and channel waveguides preserve the state of input polarization during propagation. Finally, a comparative study made between planar and channel waveguides of two different widths shows that the propagation losses decrease with the reduction in the width of the channel waveguides.
Acoustic topological systems explore topological behaviors of phononic crystals. Currently, most of the experimentally demonstrated acoustic topological systems are for airborne acoustic waves and work at or below the...
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Acoustic topological systems explore topological behaviors of phononic crystals. Currently, most of the experimentally demonstrated acoustic topological systems are for airborne acoustic waves and work at or below the kHz frequency range. Here, we report an underwater acoustic topological waveguide that works at the MHz frequency range. The 2D topological waveguide was formed at the interface of two hexagonal lattices with different pillar radii that were fabricated with metal additive manufacturing. We demonstrated the existence of edge stages both numerically and in underwater experiments. Our work has potential applications in underwater/biomedical sensing, energy transport, and acoustofluidics.& nbsp;Published under an exclusive license by AIP Publishing.
Controlling the filamentation of ultrashort and intense near-infrared laser pulses in air is crucial for many applications. For this purpose, tuning the phase of the laser beam provides a convenient way to change its ...
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ISBN:
(纸本)9798350345995
Controlling the filamentation of ultrashort and intense near-infrared laser pulses in air is crucial for many applications. For this purpose, tuning the phase of the laser beam provides a convenient way to change its far field intensity distribution. In particular, a vortex beam generated by a spiral phase plate can produce a stable ring profile with a rotating spatial phase [1], [2]. This phase momentum makes it more suitable for telecommunications through atmospheric turbulences [3] and allows the organization of multiple filaments in a cylindrical shape that is optimal to guide electromagnetic waves [4].
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