Tomasz P. Jannson

Temporal self-imaging effect in single-mode fibers

The transfer of information in fibers with a large dispersion of the first order is accomplished by a temporal analog of the self-imaging effect. The simulation of signal propagation in a single-mode fiber is considered by using the analogous Fresnel diffraction experiment.

Information capacity of Bragg holograms in planar optics

The analysis of structural information of planar holograms (i.e., “surface” holograms in integrated optics) is presented by using Ewald’s construction and a grating vector uncertainty theorem. The influences of the geometry and the material constants of the holographic system, the modulation transfer function, and dimensions of the hologram are given. A new approach to the transfer of information, connected with multimode operation, is presented.

Large fanout optical interconnects using thick holographic gratings and substrate wave propagation

Substrate wave propagation and Bragg diffraction by multiplexed holographic gratings have been used to demonstrate a new 1-to-30 fanout optical interconnect having an overall diffraction efficiency of 87.8% at 514.5 nm and an individual channel efficiency of approximately 3.0 +/- 0.8%. The device configuration utilizes the large multiplexing capability of dichromated gelatin polymer films and substrate total internal reflection to realize large channel fanouts within the plane of a soda-lime glass substrate. A simplified theoretical formulation is presented to treat the corresponding three-dimensional holographic diffraction problem in the Bragg regime for slanted phase gratings. Results are compared with experimentally measured quantities for singly exposed phase gratings in different polarization conditions and incident angle orientations. The limitations of using multiplexed holograms in multiplanar substrate interconnection applications are also discussed.

Spatial coherence discrimination in scattering

Expressions are derived, valid within the accuracy of the first Born approximation, for the cross-spectral density and for the spectral intensity of the field that is produced by scattering of radiation of any state of spatial coherence. The results are illustrated by examples that show quantitatively the difference between scattering of laser light and of ambient light. It is suggested that the dependence of the scattered intensity on the degree of spatial coherence of the incident radiation could be utilized to make devices that would discriminate between a laser beam and diffuse light.

Five-channel polymer waveguide wavelength division demultiplexer for the near infrared

A five-channel wavelength division demultiplexer (WDDM) fabricated in polymer gelatin waveguides and operating over a 100-nm bandwidth centered at 770 nm in the near infrared is discussed. The device has a maximum diffraction efficiency of 80% at 730 nm, has a spectral bandwidth of 17+or-3 nm per channel, and effectively utilizes a portion of the large optical transparency bandwidth ( approximately 2400 nm) of the photo-lime gelatin polymer material at laser diode wavelengths. High-channel-density WDDM devices at longer infrared wavelengths should be possible.<<ETX>>

Wavelength-division multiplexing and demultiplexing on locally sensitized single-mode polymer microstructure waveguides

A four-channel wavelength-division-(de)multiplexing [WD(D)M] device, operating over optical wavelengths of 543.0 to 632.8 nm, has been successfully fabricated on newly developed locally sensitized polymer (photo-lime gelatin) microstructure waveguides (PMSWs). The WD(D)M device exhibits a cross talk of less than -40 dB between adjacent channels and a diffraction efficiency of better than 50%. The angular and spectral bandwidths for the device are ~0.2-0.4 degrees and ~4-10 nm, respectively. Such sensitivities can significantly increase the WD(D)M channel density for optical interconnect architectures. Since the PMSW device can be constructed on a variety of substrates, including insulators, semiconductors, conductors, and ceramics, the demultiplexing technique that we report is suitable for use in a variety of optical-computing, signal-processing, and communication applications.

60 GHz board‐to‐board optical interconnection using polymer optical buses in conjunction with microprism couplers

We have demonstrated for the first time 60 GHz wide‐band board‐to‐board optical interconnection with a signal‐to‐noise ratio of 22 dB. The total interconnection distance is 55 cm from the input coupling prism to the detector. Board‐to‐board optical interconnection was realized using microprisms which had a measured coupling bandwidth of more than 250 nm. The graded index of the polymer waveguide allows us to implement such an interconnection scheme on an array of substrates. The elimination of backplane interconnection greatly enhances the interconnection speed. The implementation of a high‐speed on‐board transceiver in connection with a polymer waveguide lens will generate a fully on‐board optical interconnect involving modulation/demodulation.

Radiance transfer function

The transformation of generalized radiance by space-invariant linear systems, based on Walther’s second definition is analyzed. The transfer function for a generalized radiance function is introduced. Its form in the case of quasihomogeneous sources is discussed on the basis of two important examples: free space and an isoplanatic optical system.

Stratified volume diffractive elements: modeling and applications

We investigated a new type of optical element: volume diffractive optical element (VDOE). The uniqueness of the VDOE approach lies in the fact that it can exhibit a high diffraction efficiency (indigenous to a volume holographic optical element (HOE), while sporting a multi-diffractive layer structure amenable to standard lithographic manufacturing techniques. Computer design flexibility and the capability of effecting an arbitrary phase function in a VDOE provide a number of potential applications for these optical elements. Specifically, space telescope and image multiplication are discussed. Our theoretical modeling of the VDOE utilizes the rigorous coupled wave theory, which allows us to introduce an arbitrary VDOE/spacer layer thicknesses, grating slant angles, wavelengths, and incident angles. In addition, our model can simulate a multi-layer phase shifted VDOE structure (important in simulating HOE structures by a multi-layer VDOE design).

Tunable holographic Fabry–Perot étalon fabricated from poor-quality glass substrates

A novel holographic recording method has been demonstrated for fabricating highly reflectant mirror coatings on a glass substrate of poor surface quality. Electro-optically tunable characteristic fringes of a high-finesse Fabry-Perot étalon have been observed from a cavity consisting of a thin nematic liquid-crystal layer and coated with holographic mirrors. Good agreement has been found between measured values and values predicted by coupledwave theory.