1,721,091 research outputs found
Precision dicing and micromilling of silica for photonics
No full textThis thesis focuses on the development of precision dicing and micromilling machining techniques for silica photonic applications. Comparison is given between the studied and conventional techniques for machining silica, such as photolithography and etching, laser machining, etc..Precision dicing was used to create low loss input/output facets in the silica-on-silicon platform. It was demonstrated that ductile type dicing can produce facets in a silica-on-silicon substrate with a smooth, mirror like finish. The facet had a surface roughness (Sa) of 4.9 nm, a factor of ~7.5 improvement on previously reported roughnesses. An individual silica/air average interface loss, caused by surface roughness scatter, was calculated to be -0.63 dB and -0.76 dB for the TE and TM polarisations, respectively.Utilising dicing, glass photonic microcantilever devices are produced with integrated Bragg gratings and waveguides. Two cantilever interrogations methods have been shown; one utilising a single Bragg grating and the other using a pair of spectrally matched Bragg gratings to form a Fabry-Pérot interferometer. These cantilever devices were subjected to physical stimulus of external pressure change and profilometer actuation.A precision micromill was built by the author. Precision micromilling was used to remove the cladding material from the silica-on-silicon platform, for evanescent field access. By accessing the ductile milling regime, the mill enabled three-dimensional machining of flat, smooth, chip free grooves in silica. A groove with an average surface roughness (Sa) of 3.0 nm was measured, with a depth of cut of 17 µm. This micromilling method produces grooves that are seven times smoother and cut depths forty times deeper, than previously reported in the literature
Ductile dicing of LiNbO3 ridge waveguide facets to achieve 0.29 nm surface roughness in single process step
No full textDuctile dicing of LiNbO3 ridge waveguide facets to achieve 0.29 nm surface roughness in single process step
Fig. 2 Lapped and polished rib PPLN waveguide
The black dashed line shows the area where surface roughness was measured
using a Zemetrics Zescope white light interferometer. Polynomial levelling
was applied to each 11 × 6 μm2 area before roughness values were
calculated.
Fig. 3 Ductile dicing of ridge PPLN waveguide with resin bonded blade
The black dashed line shows the area where surface roughness was measured
using a Zemetrics Zescope white light interferometer. Polynomial levelling
was applied to each 11 × 6 μm2 area before roughness values were
calculated.
Fig. 4 Ductile dicing of rib PPLN waveguide with nickel bonded blade
The black dashed line shows the area where surface roughness was measured
using a Zemetrics Zescope white light interferometer. Polynomial levelling
was applied to each 11 × 6 μm2 area before roughness values were
calculated.</span
ZnO indiffused MgO:PPLN ridge waveguides
No full textData for the published paper: Carpenter, L. G., Berry, S., Bannerman, R., Gray, A. C., & Gawith, C. (2019). ZnO indiffused MgO:PPLN ridge waveguides. Optics Express, 27(17), 24538-24544. DOI: 10.1364/OE.27.024538 </span
Optically integrated fiber: a new platform for harsh environmental sensing
No full textThis work reports a new optical platform that directly integrates optical fiber upon a planar substrate. The fabrication methodology uses flame hydrolysis deposition to form an optically dynamic as well as mechanically strong composite. The resulting platform is conducive to planar fabrication techniques enabling MEMS microstucturing; mechanically continuous on-chip-off-chip interconnects, removing the dependency upon traditionally vulnerable coupling methods; and is compatible with Bragg grating inscription, permitting multiplexed multiparameter sensing. Chemical sensing is demonstrated through on-chip evanescent field exposure and physical sensing is demonstrated through use of integrated microstructures
Facet machining of silica waveguides with nanoscale roughness without polishing or lapping
No full textTo achieve low-loss free space coupling for integrated optics, device facets need to be smooth, free of chips and flat. The typical route for accomplishing these requirements is by traditional lapping and polishing. We report that high quality optical quality facets with a Sa = 4.9 nm can be machined using a simple dicing technique. In order to directly measure the scatter loss a device with a series of Bragg gratings is used to characterise the average interface loss per facet
Dataset underpinning "Quasi-Phase-Matched Materials for Active Sensing in the Mid-Infrared Waveband"
No full textData collected as part of the Southampton University Doctoral Thesis "Quasi-Phase-Matched Materials for Active Sensing in the Mid Infrared Waveband". Includes metrology and transmission data of various methods of machining and bonding GaAs and BK7 structures. Additionally spectral information relating to nonlinear generation in a PPLN OPO, RTA OPA and InF3 fibre. This dataset represents raw measured data used to generate many of the graphs and figures in the thesis.</span
Miniaturization of Bragg-multiplexed membrane transducers
No full textThis paper reports the miniaturization of Bragg-multiplexed pressure sensing membranes for integrated photonic chips. The analysis compares a novel Fabry-Pérot Bragg grating (FPBG) design that integrally spans a thin (54 µm) silica membrane to a recently reported single Bragg grating (BG) design that resides within the membrane. Unlike the single BG, the FPBG maintains spectral integrity as the dimensions of the membrane become sub-millimetre. In addition it is shown that the FPBG structure can also be used for inherent temperature referencing, having a Bragg thermal sensitivity of 13.5 pm °C-1, which can be decoupled from pressure effects. For the reported sub-millimetre membrane, pressure resolution was enhanced by a factor of three and spectral bandwidth reduced by over five-fold
Microfluidic multimode interference device
No full textA multimode interference device has been fabricated using a novel ultra-precision micromachining technique. The micromachining technique defines the interfaces of the device by cutting microfluidic channels into a silica-on-silicon substrate. Changing the refractive index of fluid within these microfluidic channels is shown to alter the optical characteristics of the device
Zinc indiffused PPLN ridge waveguides
No full textWe demonstrate zinc-indiffused PPLN ridge waveguides with insertion losses of 1.8 dB in 3.4 cm long devices with standard telecommunication fiber butt coupling. Low insertion losses are critical for enabling compact, high-efficiency 780 nm wavelength converted laser sources for space-based Rubidium atom cooling systems. Our low insertion losses are attributed to sub-nanometer waveguide sidewall surface roughness produced by ultra precision ductile mode dicing. Surface roughnesses of 0.29 nm have been measured, demonstrating an order of magnitude reduction compared to prior art. We will present our latest work on zinc-indiffused PPLN ridge waveguides and report on ultra precision ductile mode dicing for PPLN ridge waveguide fabrication
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