J. C. Knight

Publication List Details

Period

1973 - 2009

Number

176

Co-Authors

Remote System for Detection of Low-Levels of Methane Based on Photonic Crystal Fibres and Wavelength Modulation Spectroscopy (2009)

J. P. Carvalho, H. Lehmann, H. Bartelt, F. Magalhães, R. Amezcua-Correa, J. L. Santos, ...

In this work we described an optical fibre sensing system for detecting low levels of methane. The properties of hollow-core photonic crystal fibres are explored to have a sensing head with...

Remote System for Detection of Low-Levels of Methane Based on Photonic Crystal Fibres and Wavelength Modulation Spectroscopy (2009)

J. P. Carvalho, H. Lehmann, H. Bartelt, F. Magalhães, R. Amezcua-Correa, J. L. Santos, ...

In this work we described an optical fibre sensing system for detecting low levels of methane. The properties of hollow-core photonic crystal fibres are explored to have a sensing head with...

Genetics and the general physician: insights, applications and future challenges (2009)

Knight, J.C.

Scientific and technological advances in our understanding of the nature and consequences of human genetic variation are now allowing genetic determinants of susceptibility to common multifactorial...

Modal interferometer based on hollow-core photonic crystal fiber for strain and temperature measurement (2009)

Aref, S. H., Amezcua Correa, R., Carvalho, J. P., Frazao, O., Caldas, P., Santos, J. L., ...

In this work, sensitivity to strain and temperature of a sensor relying on modal interferometry in hollow-core photonic crystal fibers is studied. The sensing structure is simply a piece of...

Multi-wavelength source at ITU-T grid based on ultra-flattened dispersion photonic crystal fibers (2008)

S. Jr., Arismar Cerqueira, Marconi, J. D., Gabrielli, L. H., Rieznik, A. A., Hernandez-Figueroa, H. E., Fragnito, H. L., ...

We report on the development of a multi-wavelength source locked to the ITU-T grid at 100 GHz spacing and based on ultra-flattened dispersion photonic crystal fibers. The ITU-T grid frequencies are...

Control surface modes in low loss hollow-core photonic bandgap fibers (2008)

Amezcua-Correa, R., Gérôme, F., Leon-Saval, S., Broderick, N.G.R., Birks, T.A., Knight, J.C.

We report low-loss hollow-core photonic bandgap fibers free from surface modes. They have low attenuation over the full spectral width of the bandgap, and approximately halved dispersion and...

Control of surface modes in low loss hollow-core photonic bandgap fibers (2008)

Amezcua-Correa, R., Gèrôme, F., Leon-Saval, S.G., Broderick, N.G.R., Birks, T.A., Knight, J.C.

We report on the fabrication and characterization of hollow-core photonic bandgap fibers that do not suffer from surface mode coupling within the photonic bandgap of the cladding. This enables low...

Control of surface modes in low loss hollow-core photonic bandgap fibers (2008)

Amezcua-Correa, R., Gerome, F., Leon-Saval, S., Broderick, N. G. R., Birks, T. A., Knight, J. C.

We report low-loss hollow-core photonic bandgap fibers free from surface modes. They have low attenuation over the full spectral width of the bandgap, and approximately halved dispersion and...

Control of Surface Modes in Low Loss Hollow-Core Photonic Bandgap Fibers (2008)

Amezcua-Correa, R, Gerome, R, Leon-Saval, S., Broderick, N. G. R., Birks, T. A., Knight, J. C.

We report low-loss hollow-core photonic bandgap fibers free from surface modes. They have low attenuation over the full spectral width of the bandgap, and approximately halved dispersion and...

Compression of picosecond optical pulses in tapered hollow-core photonic bandgap fiber (2008)

Cook, K, Welch, M. G., Gerome, F, George, A. K, Wadsworth, W. J., Knight, J. C.

We demonstrate nonlinear compression of 2.5ps and 1.2ps laser pulses at 800nm wavelength using a 35m tapered hollow-core photonic bandgap fiber with continuously-decreasing dispersion.

Visibly "White" Light Generation in Uniform Photonic Crystal Fiber Using a Microchip Laser (2008)

Stone, J. M., Knight, J. C., Clowes, J.

We describe how to extend the bandwidth of the supercontinuum generated in uniform fibers pumped at 1064nm. The spectra extend to similar to 400nm, some 50nm deeper into the blue than previously with...

935nm Nd/sup 3+/ fibre laser incorporating tapered photonic bandgap fibre filter (2007)

Wang, A., Ding, W., Birks, T. A., Knight, J. C.

An 8 cm length of photonic bandgap fibre was tapered in the middle to narrow the transmission windows. The tapered fibre was incorporated into a neodymium fibre laser system, in which it suppressed...

Hollow-core photonic crystal fibres for delivery and compression of ultrashort optical pulses (2007)

Knight, J. C., Gerome, F., Wadsworth, W. J.

We describe the use of tapered hollow-core photonic crystal fibres for delivery and compression of ultrashort optical pulses. We demonstrate delivery of transform-limited pulses with less than 100 fs...

Characterization of frequency noise on a broadband infrared frequency comb using optical heterodyne techniques (2007)

Kim, K., Nicholson, J. W., Yan, M., Knight, J. C., Newbury, N. R., Diddams, S. A.

We measure the frequency noise across a Cr: forsterite infrared frequency comb through the optical heterodyne beat of different comb teeth against stable continuous wave (CW) lasers. This sensitive...

65 THz beat frequency observed from a scalar modulation instability experiment (2005)

Kruhlak, Robert, Wong, Gordon, Clark, Heather, Leonhardt, Rainer, Harvey, John, Knight, J C, ...

Items in ResearchSpace are protected by copyright, with all rights reserved, unless otherwise indicated. Previously published items are made available in accordance with the copyright policy of the...

Achieving low loss and low nonlinearity in hollow core photonic crystal fibers (2005)

Roberts, P. J., Couny, F., Birks, T. A., Knight, J. C., St Russell, P. J., Mangan, B. J., ...

Loss and nonlinearity in hollow core photonic crystal fibers are shown to be simultaneously reduced by the incorporation of anti-resonant features within the boundary region between the core and the...

A single-material glass-web optical fiber (2005)

Joly, N. Y., Yulin, A., Knight, J. C., Birks, T. A., Russell, P. St J.

We present a glass-web fiber waveguide made by the stack and draw method used in photonic crystal fiber manufacturing. Nonlinear behavior such as the cancellation of self-frequency shift are reported.

The fundamental limits to the attenuation of hollow-core photonic crystal fibres (2005)

Birks, T. A., Roberts, P. J., Couny, F., Sabert, H., Mangan, B. J., Williams, D. P., ...

We propose that the transmission of hollow-core photonic crystal fibres is ultimately limited by scattering from roughness due to frozen-in surface capillary waves. This is confirmed by measurements...

All-fiber single-mode hollow-core gas cells for stimulated Raman scattering and laser frequency stabilization (2005)

Benabid, Fetah, Couny, F., Knight, J. C., Birks, T. A., Russell, P. St J.

Gas-filled hollow-core photonic crystal fiber (HC-PCF) is hermetically spliced to standard single-mode fiber with low insertion-loss. A hydrogen-filled HC-PCF based quasi-CW Raman converter and an...

Efficient hierarchic management for reconfiguration of networked information systems (2004)

J. C. Rowanhill, P. E Varner, J. C. Knight

The management of modern distributed systems is complicated by scale and dynamics. The continued effectiveness of an authoritative ('top-down') approach depends on its ability to handle...

Dispersion and refractive index measurement for Ge, B-Ge doped . . . (2004)

W.N. MacPherson, A Fern, Ez Fern, B Brichard, F Berghmans, J C Knight, ...

We have investigated the effects of ionizing radiation-induced changes on dispersion and refractive index in photonic crystal fibre, boron co-doped photosensitive fibre and standard SMF-28 fibre up...

Compact supercontinuum generation and four-wave mixing in PCF with 10 ns laser pulses (2004)

Wadsworth, W. J., JoIy, N. Y., Biancalana, F., Knight, J. C., Birks, T. A., Russell, P. St J.

We report broad flat supercontinuum, 500-1750+ nm, using a kHz train of nanosecond Q-switched microchip laser pulses at 1064 nm or 1047 nm. The same systems exhibit strong parametric generation of...

Low loss (1.7 dB/km) hollow core photonic bandgap fiber (2004)

Mangan, B. J., Farr, L., Langford, A., Roberts, P. J., Williams, D. P., Couny, F., ...

We report a silica hollow core photonic bandgap fiber with a minimum attenuation of 1.72 dB/km at 1565 nm wavelength and discuss the scaling of attenuation with wavelength and the minimum loss...

Experimental demonstration of refractive index scaling in photonic bandgap fibers (2004)

Antonoppolos, G., Benabid, Fetah, Birks, T. A., Bird, D. M., Bouwmans, G., Knight, J. C., ...

We report on the experimental observation of the bandgap shift in D/sub 2/O-filled hollow core photonic crystal fibers. Our results confirm a simple scaling law for bandgaps in fibers with different...

Wavelength dependence of induced nonlinear effects in photonic crystal fibre (2003)

Stormont, B., Kemp, A.*, Mazilu, M., Brown, C.T.A., Wadsworth, W.J., Knight, J.C., ...

Summary form only given. In this paper, we report a systematic study of spectral effects at various wavelengths relative to the zero group velocity dispersion (GVD) point in the fibre. The fibres...

Wavelength dependence of induced nonlinear effects in photonic crystal fibre (2003)

Stormont, B., Kemp, A., Mazilu, M., Brown, C.T.A., Wadsworth, W.J., Knight, J.C., ...

Summary form only given. In this paper, we report a systematic study of spectral effects at various wavelengths relative to the zero group velocity dispersion (GVD) point in the fibre. The fibres...

Wavelength dependence of induced nonlinear effects in photonic crystal fibre (2003)

Stormont, B., Kemp, A., Mazilu, M., Brown, C.T.A., Wadsworth, W.J., Knight, J.C., ...

Summary form only given. In this paper, we report a systematic study of spectral effects at various wavelengths relative to the zero group velocity dispersion (GVD) point in the fibre. The fibres...

High power photonic crystal fibre laser with very high NA pump cladding (2003)

Percival, R. M., Wadsworth, W. J., Bouwmans, G., Knight, J. C., Birks, T. A., Hedley, T. D., ...

4 W of laser power at 1040 nm has been achieved for the first time from an Yb-doped double clad PCF. The inner cladding of this fibre has the highest NA yet reported of 0.7-0.8.

High power Er/Yb fiber laser with very high numerical aperture pump cladding waveguide (2003)

Bouwmans, G., Percival, R. M., Wadsworth, W. J., Knight, J. C., Birks, T. A., Russell, P. St J.

High power Er/Yb lasers at 1.55 /spl mu/m are attractive for a number of applications, for example sensors, spectroscopy and free space telecommunications. In this paper, we report a double-clad...

Photonic crystal fibres for sensor applications (2002)

Jones, J. D. C., Knight, J. C., Birks, T. A.

Photonic crystal fibres (PCF) offer extraordinary control over their waveguiding properties via the geometry of their microstructure. We shall describe the design principles for PCF, their practical...

Using photonic crystals as optical fibers (2001)

Knight, J. C., Birks, T. A., Mangan, B. J., Russell, P. St J.

By designing and fabricating optical fibers using photonic crystal materials as cladding, one can create fibers with previously unimaginable waveguiding properties. The development of photonic...

Directional coupling in a twin core photonic crystal fiber using heat treatment (2001)

Kakarantzas, G., Mangan, B. J., Birks, T. A., Knight, J. C., Russell, P. S. J.

Summary form only given. We demonstrate an evanescent field coupler by selective heat-treating a region of a previously uncoupled twin core PCF. The twin-core PCF presented in this paper was...

Digital Computer Simulation of Tactical Situations. (1998)

Knight, J. C.

This memorandum is a summary of work done in the field of simulation. The emphasis is on methodology rather than results. The techniques described are extremely simple, and should be easily adaptable...

The Fine-Scale Microstructure of Thin Hard TiN and TiC Coatings on Steels. (1998)

Knight, J. C., Page, T. F.

X-ray diffraction (XRD) and transmission electron microscopy (TEM) have been used to investigate the fine-scale microstructure of TiN and TiC obtained by chemical vapor deposition (CVD) and a range...

Two categories of synovial sarcoma defined by divergent chromosome translocation breakpoints in Xp11.2, with implications for the histologic sub-classification of synovial sarcoma (1995)

Reeves, B R, Fletcher, C D, Kempski, H, ...

Molecular analysis of a new series of synovial sarcomas confirms that t(X;18)(p11.2;q11.2) breakpoints occur at two distinct regions on Xp designated SS1 and SS2. Breakpoint position correlates with...

The mechanical properties of highly porous ceramics. (1982)

Knight, J. C.

Thesis (Ph. D.)--University of Cambridge, 1982.

A LANGUAGE DESIGN FOR VECTOR MACHINES (1975)

V. R. Basili, J. C. Knight, V. R. Basili, J. C. Knight

This paper deals with a programming language under development at NASA's Langley Research Center for the CDC STAR-100. The design goals for the language are that it be basic in design and able...

PCR strategy for identification and differentiation of small pox and other orthopoxviruses.

Ropp, S L, Jin, Q, Knight, J C, Massung, R F, Esposito, J J

Rapid identification and differentiation of orthopoxviruses by PCR were achieved with primers based on genome sequences encoding the hemagglutinin (HA) protein, an infected-cell membrane antigen that...

PCR strategy for identification and differentiation of small pox and other orthopoxviruses.

Ropp, S L, Jin, Q, Knight, J C, Massung, R F, Esposito, J J

Rapid identification and differentiation of orthopoxviruses by PCR were achieved with primers based on genome sequences encoding the hemagglutinin (HA) protein, an infected-cell membrane antigen that...

Outbreak of human monkeypox, Democratic Republic of Congo, 1996 to 1997.

Hutin, Y. J., Williams, R. J., Malfait, P., Pebody, R., Loparev, V. N., Ropp, S. L., ...

Human monkeypox is a zoonotic smallpox-like disease caused by an orthopoxvirus of interhuman transmissibility too low to sustain spread in susceptible populations. In February 1997, 88 cases of...

Structural alterations of the RB1 gene in human soft tissue tumours.

Stratton, M. R., Williams, S., Fisher, C., Ball, A., Westbury, G., Gusterson, B. A., ...

Sixty-nine primary soft tissue tumours were examined for alterations of the RB1 gene which has previously been implicated in the genesis of retinoblastoma. In three tumours loss of both alleles of...

Genetics and the general physician: insights, applications and future challenges

Knight, J.C.

Scientific and technological advances in our understanding of the nature and consequences of human genetic variation are now allowing genetic determinants of susceptibility to common multifactorial...