M.N. Zervas

Surface plasmon–polariton waves guided by thin metal films

Surface plasmon-polariton modes supported by thin metal films surrounded by dissimilar semi-infinite dielectrics are studied. The dispersion of the modes is evaluated, and their characteristics are investigated when the metal film thickness and the superstrate refractive index are varied. Long-range surface plasmon-polaritons are shown to be supported even by highly asymmetric configurations.

Performance of surface-plasma-wave fiber-optic polarizers

Variations in the TM-like polarization transmission characteristics and polarization extinction ratio of surface-plasma-wave fiber-optic polarizers owing to variations in the depth of polishing and the metal film thickness are presented. The two effects have been isolated in carefully designed experiments and studied separately.

Surface plasmon-polariton fiber-optical polarizers using thin-nickel films

High-quality optical fiber polarizers fabricated by depositing thin nickel films on polished fibers are discussed. The polarization extinction is achieved by efficiently exciting TM-polarized surface plasmon-polariton waves, which are supported by the nickel films, by means of evanescent field interaction with the propagating fundamental fiber mode. TM-like polarized light is efficiently coupled and extinguished when precise phase matching conditions are achieved. The TE-like polarization, on the other hand, passes through with minimal losses. Devices with polarization extinction ratio in excess of 55 dB and insertion losses less than 1 dB have been demonstrated.<<ETX>>

Surface plasmon-polariton fiber-optic polarizers using thin chromium films

High-quality optical fiber polarizers have been fabricated by depositing thin chromium films thermally onto polished fibers. Surface plasmon-polariton (SPP) waves which are supported by the thin chromium films are optically excited by evanescent field interaction with the propagating fundamental fiber mode and utilized as the polarization selective mechanism. Transverse-magnetic-like polarized light is extinguished when precise phase-matching conditions with the symmetric-bound SPP mode are achieved. The transverse-electric-like polarization, on the other hand, passes through with minimal losses. Devices with polarization extinction ratio in excess of 50 dB and insertion losses less than 1 dB are demonstrated.<<ETX>>

Polarizing Beam Splitter Of Polished Type.

Fibre-optic polarizing beam splitters are 2x2 port components which cross-couple efficiently one input linear polarization and transmit unaffected the orthogonal one. Such a device is useful in a variety of all-fibre-optic applications such as wavelength multiplexing / demultiplexing, polarization diversity detection schemes, and fibre Raman amplifiers. The configurations reported so far consist of two single-modal low- or high-birefrigence fibres coupled together by either fusion or polishing techniques. Their function relies upon the geometrical form and/or stress-induced birefrigence introduced into the interaction area. The polarization splitting can then be described either by the use of different-coupling- coefficient arguments for the two orthogonal polarizations [1] [2], or by differential beating of the LP0 1 and LP 11 modes excited in the interaction composite region by each of the two orthogonal polarizations [3] [4]. An alternative novel approach to the same problem utilizes the polishing technique to couple the two fibres and Surface Plasmon Waves (SPWs) to achieve polarization separation [5]. A thin metal film incorporated between the two polished surfaces in the interaction area supports SPWs which are inherently TM-polarised. Therefore, in this three-waveguide structure (fibre-thin metal film-fibre) only TM-like-polarized light cross-couples efficiently while the TE-like-polarization is transmitted unaffected. A typical polarization extinction ratio of 35 dB in both arms and a polarization selectivity of 30 dB are achieved.

Optical-fiber phase modulator with enhanced modulation efficiency

A novel piezoelectrically driven optical-fiber phase modulator is described. The modulator has low thermal drift and minimum polarization modulation and is immune to variations in the characteristics of the piezoelectric transducer. The theoretical model of the modulator accurately predicts the experimental performance, showing a phase-modulation enhancement over a wraparound fiber modulator at resonance.