We report both theoretical and experimental results of a slit beam shaping configuration for fabricating photonic waveguides by use femtosecond laser pulses. Most importantly we show the method supports focusing objectives with long depth field allows direct-writing microstructures circular cross-sections whilst employing perpendicular writing scheme. applied this technique to write low loss (0.39 dB/cm), single mode in phosphate glass.

We report photonic quantum circuits created using an ultrafast laser processing technique that is rapid, requires no lithographic mask and can be used to create three-dimensional networks of waveguide devices. have characterized directional couplers--the key functional elements circuits--and found they perform as well lithographically produced further demonstrate high-performance interferometers important multi-photon interference phenomenon for the first time in integrated optics. This...

Abstract Direct‐write optical waveguide device fabrication is probably the most widely studied application of femtosecond laser micromachining in transparent dielectrics at present time. Devices such as buried waveguides, power splitters, couplers, gratings, amplifiers and oscillators have all been demonstrated. This paper reviews direct‐write technique to active devices bulk glass materials.

Optical waveguides that incorporate Bragg gratings have been written in bulk fused silica by using the femtosecond laser direct-write method and without need for lithography or ion-beam techniques. A single manufacturing process is used to create waveguide-Bragg grating reflectors operation C band.

We report a 790 nm pumped, Tm³⁺ doped ZBLAN glass buried waveguide laser that produces 47 mW at 1880 nm, with 50% internal slope efficiency and an M² of 1.7. The cladding is defined by two overlapping rings created femtosecond direct-writing the glass, which results in formation tubular depressed-index-cladding structure, resonator external dielectric mirrors. This is, to best our knowledge, most efficient host via writing.

Currently, direct-write waveguide fabrication is probably the most widely studied application of femtosecond laser micromachining in transparent dielectrics. Devices such as buried waveguides, power splitters, couplers, gratings, and optical amplifiers have all been demonstrated. Waveguide properties depend critically on sample material writing characteristics. In this paper, we discuss challenges facing researchers using technique with specific emphasis being placed suitability fused silica...

We report the fabrication and performance of first C-band directly written monolithic waveguide laser (WGL). The WGL device was created in an erbium- ytterbium-doped phosphate glass host consisted optical that included a distributed feedback Bragg grating structure. femtosecond direct-write technique used to create both waveguide-Bragg simultaneously single processing step. optically pumped at approximately 980 nm lased 1537 with bandwidth less than 4 pm.

Integrated optics provides an ideal testbed for the emulation of quantum systems via continuous-time walks. Here, we study evolution two-photon states in elliptic array waveguides. We characterize photonic chip coherent light tomography and use results to predict distinct differences between temporally indistinguishable distinguishable inputs, which then compare with experimental observations. This work highlights feasibility phenomena three-dimensional waveguide structures.

A femtosecond laser with a 1 kHz repetition rate and two different polarization states was used to fabricate low-loss waveguides in fused silica. Investigations of chemically-mechanically polished waveguide regions using near-field scanning optical microscopy revealed the presence modifications outside glass directly exposed circularly polarized writing laser. These also exhibited refractive index contrast up twice as large that written linearly radiation. The observed differences were shown...

In the two decades since first extra-solar planet was discovered, detection and characterization of planets has become one key endeavours in all modern science. Recently, direct techniques such as interferometry or coronagraphy have received growing attention because they reveal population exoplanets inaccessible to Doppler transit techniques, moreover allow faint signal from itself be investigated. Next-generation stellar interferometers are increasingly incorporating photonic technologies...

We compare and contrast novel techniques for the fabrication of chirped broadband fiber Bragg gratings by ultrafast laser inscription. These methods enable inscription with flexible period profiles thus tailored reflection dispersion characteristics in non-photosensitive optical fibers. Up to 19.5 cm long a spectral bandwidth up 30 nm were fabricated grating was characterized. A maximum group delay almost 2 ns obtained linearly either normal or anomalous velocity dispersion, demonstrating...

A femtosecond-laser-written monolithic waveguide laser (WGL) oscillator based on a distributed-feedback architecture and fabricated in ytterbium-doped phosphate glass is reported. The device lased at 1033 nm with an output power of 102 mW bandwidth less than 2 pm when bidirectionally pumped 976 nm. WGL was stable operated for 50 h without degradation. This demonstration high-performance opens the possibility creating variety narrow-linewidth designs bulk glasses.

Abstract Optical waveguide Bragg gratings (WBGs) can be created in transparent materials using femtosecond laser pulses. The technique is conducted without the need for lithography, ion-beam fabrication methods, or clean room facilities. This paper reviews field of ultrafast laser-inscribed WBGs since its inception, with a particular focus on techniques, WBG characteristics, types, and applications.

Optical devices were fabricated in fused silica using the femtosecond direct write technique. We found that transmission of light through directly written waveguides, whether straight or curved, can be increased by writing waveguides circularly rather than linearly polarised radiation.

The combination of ultrafast laser inscription and engineered soft glasses is enabling a new class photonic devices offering long wavelength transparency, high nonlinearity, optical gain. However, this field research also possesses its own unique set fabrication challenges, which range from the predictable, such as self‐focusing effects, material stress, damage to unexpected, photo‐induced index changes different sign. In article, we review many challenges surrounding laser‐written...

The mid-infrared wavelength regime 3.5 -4.1μm, known as the astronomical L' band is of special interest for exoplanet hunting.Mid-IR compatible photonic technologies are an enabling platform a range critical observational science using compact instruments on next generation Extremely Large Telescopes.Pupil remapping interferometry technique in which subapertures telescope pupil (2D) reformatted into 1D linear array.This can be done efficiently 3D photonics.One most important techniques to...

We report the development of a widely tunable all-fiber mid-infrared laser system based on mechanically robust fiber Bragg grating (FBG) which was inscribed through polymer coating Ho3+-Pr3+ co-doped double clad ZBLAN fluoride by focusing femtosecond pulses into core without use phase mask. By applying mechanical tension and compression to FBG while pumping with an 1150 nm diode, continuous wave (CW) tuning range 37 nm, centered at 2870 demonstrated up 0.29 W output power. These results pave...

We report the direct femtosecond laser inscription of type-I fiber Bragg gratings (FBGs) into core soft-glass ZBLAN fibers. investigate and compare various fabrication methods such as single pass (line by line), double pass, stacking (plane plane) to create highest reflectivity FBGs (99.98%) for mid-infrared (mid-IR) applications. In addition, we experimentally demonstrate how parameters that influence coupling coefficient, i.e., refractive index modulation overlap factor, can be controlled...

We report on the fabrication of, to best of our knowledge, first highly reflective fiber Bragg gratings for 4 µm wavelength range. A second-order grating with a coupling coefficient (κ) 230m-1, losses <0.25dB/cm, and bandwidth approximately 3 nm was inscribed into core passive indium fluoride (InF3) using femtosecond (fs) laser. Thermal annealing this at temperature 150°C 90 min resulted in enhancement κ 275m-1. Further, we show that InF3 fibers respond very differently irradiation fs laser...

Abstract A general picture of refractive index change mechanisms in glass modified by a femtosecond laser has proven elusive. In this paper, Raman microscopy was used conjunction with near‐field profilometry to analyse the structure borosilicate (Schott BK7) and determine mechanism observed change. For pulse repetition rate 1 kHz, it determined that due an elevated population non‐bridging oxygen atoms, resulting more ionic bonds forming within network increasing molar refractivity glass. 5.1...

Raman microscopy and refractive near-field profilometry were used to analyze waveguides written in Yb-doped Kigre QX glass under the low repetition-rate (noncumulative-heating) regime. It was found that femtosecond-laser induced index change due an increase proportion of Q1 P-tetrahedra associated polarizability glass. The role color center formation removal this process is clearly defined, phosphorous–oxygen hole centers (POHCs) PO3− ions form as a result P–O bonds being broken during...

There is still significant speculation regarding the nature of femtosecond laser induced index change in bulk glasses with colour centre formation and densification main candidates. In work presented here, we fabricated waveguide Bragg gratings doped undoped phosphate use these as a diagnostic for monitoring subtle changes refractive during photo- thermal annealing experiments. Reductions grating strengths such experiments were attributed to annihilation centres.

Chalcogenide glasses are of great interest for a variety applications, such as nonlinear optics, sensing and astronomy due to their high optical nonlinearity, broad infrared transparency well photosensitivity. We report detailed comparison the inscription single-mode waveguides in gallium lanthanum sulphide chalcogenide glass using 800 nm femtosecond lasers. The athermal thermal fabrication regimes explored by laser repetition rates between 1 kHz 5.1 MHz. Three different techniques exploited...

Strong waveguide Bragg gratings (10.5 dB transmission dip) were fabricated using the femtosecond (fs) laser direct-write technique in ZBLAN glass. The are based on depressed cladding waveguides and consist of planes, periodic according to condition, which constructed from a transverse hexagonal lattice smaller point features. Such key step toward realization mid-infrared monolithic lasers fs technique.