Abstract: An electra-absorption modulator and electra-absorption modulated laser are described that include a semiconductor layer having an electrically controllable absorption. The material composition of the semiconductor layer is chosen so that the semiconductor layer is substantially transparent to light propagating through the semiconductor layer when a substantially zero or a reverse bias voltage is applied across the semiconductor layer at operating temperatures of the electro-absorption modulator that are substantially greater than 25 degrees Celsius.

Abstract: Methods and apparatus for generating strongly-ionized plasmas are disclosed. A strongly-ionized plasma generator according to one embodiment includes a chamber for confining a feed gas. An anode and a cathode assembly are positioned inside the chamber. A pulsed power supply is electrically connected between the anode and the cathode assembly. The pulsed power supply generates a multi-stage voltage pulse that includes a low-power stage with a first peak voltage having a magnitude and a rise time that is sufficient to generate a weakly-ionized plasma from the feed gas. The multi-stage voltage pulse also includes a transient stage with a second peak voltage having a magnitude and a rise time that is sufficient to shift an electron energy distribution in the weakly-ionized plasma to higher energies that increase an ionization rate which results in a rapid increase in electron density and a formation of a strongly-ionized plasma.

Abstract: According to various embodiments and aspects of the present invention, there is provided a dynamically tunable thin film interference coating including one or more layers with thermo-optically tunable refractive index. Tunable layers within thin film interference coatings enable a new family of thin film active devices for the filtering, control, modulation of light. Active thin film structures can be used directly or integrated into a variety of photonic subsystems to make tunable lasers, tunable add-drop filters for fiber optic telecommunications, tunable polarizers, tunable dispersion compensation filters, and many other devices.

Abstract: An atomic layer deposition system is described that includes a deposition chamber. A first and second reaction chamber are positioned in the deposition chamber and contain a first and a second reactant species, respectively. A monolayer of the first reactant species is deposited on a substrate passing through the first reaction chamber. A monolayer of the second reactant species is deposited on a substrate passing through the second reaction chamber. A transport mechanism transports a substrate in a path through the first reaction chamber and through the second reaction chamber, thereby depositing a film on the substrate by atomic layer deposition. The shape of the first and the second reaction chambers are chosen to achieve a constant exposure of the substrate to reactant species when the transport mechanism transports the substrate in the path through the respective reaction chambers at the constant transport rate.

Abstract: Methods and apparatus for generating uniformly-distributed plasma are described. A plasma generator according to the invention includes a cathode assembly that is positioned adjacent to an anode and forming a gap there between. A gas source supplies a volume of feed gas and/or a volume of excited atoms to the gap between the cathode assembly and the anode. A power supply generates an electric field across the gap between the cathode assembly and the anode. The electric field ionizes the volume of feed gas and/or the volume of excited atoms that is supplied to the gap, thereby creating a plasma in the gap.

Abstract: Magnetically enhanced plasma processing methods and apparatus are described. A magnetically enhanced plasma processing apparatus according to the present invention includes an anode and a cathode that is positioned adjacent to the anode. An ionization source generates a weakly-ionized plasma proximate to the cathode. A magnet is positioned to generate a magnetic field proximate to the weakly-ionized plasma. The magnetic field substantially traps electrons in the weakly-ionized plasma proximate to the cathode. A power supply produces an electric field in a gap between the anode and the cathode. The electric field generates excited atoms in the weakly-ionized plasma and generates secondary electrons from the cathode. The secondary electrons ionize the excited atoms, thereby creating a strongly-ionized plasma.

Abstract: The invention relates to suppression of high frequency resonance in an electro-optical device. The electro-optical device includes an optical waveguide formed in a substrate and a plurality of electrically floating electrode segments that are positioned on the substrate to intensify an electric field in the optical waveguide. The device also includes a RF ground electrode that is positioned on the substrate. The RF ground electrode defines a slot having a shape that suppresses modal conversion and propagation of high order modes in the RF ground electrode and in the plurality of electrically floating electrode segments, thereby suppressing modal coupling to the substrate. The device further includes a buffer layer formed on the upper surface of the substrate, on the plurality of electrically floating electrode segments, and in the slot. A driving electrode receives a RF signal that induces-the electric field in the optical waveguide.

Abstract: Methods and apparatus for generating a strongly-ionized plasma are described. An apparatus for generating a strongly-ionized plasma according to the present invention includes an anode and a cathode that is positioned adjacent to the anode to form a gap there between. An ionization source generates a weakly-ionized plasma proximate to the cathode. A power supply produces an electric field in the gap between the anode and the cathode. The electric field generates excited atoms in the weakly-ionized plasma and generates secondary electrons from the cathode.

Abstract: The plasma source includes a cathode assembly. An anode is positioned adjacent to the cathode assembly. An excited atom source generates an initial plasma and excited atoms from a volume of feed gas. The initial plasma and excited atoms are located proximate to the cathode assembly. A power supply generates an electric field between the cathode assembly and the anode. The electric field super-ionizes the initial plasma so as to generate a high-density plasma.

Abstract: The plasma source includes a cathode assembly having an inner cathode section and an outer cathode section. An anode is positioned adjacent to the outer cathode section so as to form a gap there between. A first power supply generates a first electric field across the gap between the anode and the outer cathode section. The first electric field ionizes a volume of feed gas that is located in the gap, thereby generating an initial plasma. A second power supply generates a second electric field proximate to the inner cathode section. The second electric field super-ionizes the initial plasma to generate a plasma comprising a higher density of ions than the initial plasma.

Abstract: The present invention relates to a plasma generator that generates a plasma with a multi-step ionization process. The plasma generator includes an excited atom source that generates excited atoms from ground state atoms supplied by a feed gas source. A plasma chamber confines a volume of excited atoms generated by the excited atom source. An energy source is coupled to the volume of excited atoms confined by the plasma chamber. The energy source raises an energy of excited atoms in the volume of excited atoms so that at least a portion of the excited atoms in the volume of excited atoms is ionized, thereby generating a plasma with a multi-step ionization process.

Abstract: An ion storage system is described that includes an ion trap that defines a volume for storing a plurality of ions. A radio frequency (RF) generator is electromagnetically coupled to the volume defined by the ion trap. The RF generator generates an RF electrical field that stores the plurality of ions in the ion trap. A switching device terminates the RF electrical field, which ejects the plurality of ions from the ion trap. An ion detector detects at least a portion of the plurality of ions that are ejected from the ion trap.

Abstract: An acousto-optic tunable filter that includes a polarization beamsplitter, a multi-segment interaction region and a polarization beam combiner is described. The polarization beamsplitter generates a first and a second polarized optical signal. The multi-segment optical interaction region includes a first optical interaction region and a first acoustic wave generator that generates acoustic waves in the first optical interaction region. The multi-segment optical interaction region also includes a second optical interaction region that is non-collinear relative to the first optical interaction region and a second acoustic wave generator that generates acoustic waves in the second optical interaction region. Optical signals that are phase-matched to the acoustic waves are mode-converted in response to the acoustic waves. The acousto-optic tunable filter also includes a polarization beam combiner that generates both a mode-converted optical signal and a non-mode-converted optical signal.

Abstract: A climbing-traversing wall, designed to be installed as one of a group, is constructed with two opposite-facing surfaces positioned about a vertical axis such that the climbing wall may be pivoted about its central axis thus allowing the group of climbing walls to be adjusted to a variety of maze-like configurations.

Abstract: The invention relates to apparatus and methods for suppressing high frequency resonance in an electro-optical device. The electro-optical device includes an optical waveguide formed in the upper surface of a substrate. The device further includes a plurality of electrically floating electrode segments that are positioned on the substrate to intensify an electric field in the optical waveguide. The device also includes a plurality of electrically grounded electrode segments that are positioned on the substrate for prohibiting modal conversion and propagation of high order modes in the plurality of electrically grounded electrode segments and in the plurality of electrically floating electrode segments, thereby suppressing modal coupling to the substrate. The device further includes a buffer layer formed on the upper surface of the substrate and a driving electrode formed on an upper surface of the buffer layer for receiving an RF signal that induces the electric field in the optical waveguide.

Abstract: A method of determining thickness and refractive index of an optical thin film is described. The method includes generating a diagnostic light beam having a first and a second wavelength. The method also includes measuring unattenuated light intensities at the first and the second wavelength of the diagnostic light beam. The method also includes measuring attenuated light intensities at the first and the second wavelength of the diagnostic light beam after transmission through the optical thin film. A null light intensity for the diagnostic light beam at the first and second wavelength is also determined. A first and second normalized intensity function is determined using the measured unattenuated light intensities, the measured attenuated light intensities, and the measured null light intensities. The thickness and refractive index of the optical thin film is then determined by solving the first and second normalized intensity function for thickness and refractive index.

Abstract: An optical data transmitter is described that includes a precoder that converts an input data signal to a binary precoded data signal and to a complementary binary precoded data signal. A delay element delays one of the complementary binary precoded data signal and the binary precoded data signal relative to the other by a time corresponding to less than one bit period of the binary precoded data signal. A differential amplifier converts the binary precoded data signal and the complementary binary precoded data signal to a four-level data signal and to a complementary four-level data signal. An optical data modulator modulates an amplitude of an optical signal applied to an optical input of the optical data modulator in response to at least one of the four-level data signal and the complementary four-level data signal to generate a modulated optical output signal.

Abstract: An optical power and wavelength monitor of an optical beam is described. The monitor includes a first detector positioned in the path of the optical beam that generates a first electrical signal that is proportional to an optical power of the optical beam. The monitor also includes an optical filter that is positioned in the path of the optical beam. The optical filter transmits a portion of the optical beam having a wavelength within a bandwidth of the optical filter. A second detector that is positioned in the path of the optical beam generates a second electrical signal that is proportional to an optical power of the filtered optical beam. A signal processor receives the first and second electrical signals and generates a signal that is proportional to the wavelength of the optical beam.

Abstract: A high-efficiency electro-optic modulator with an equalized frequency response is described. The modulator includes an optical waveguide formed in an electro-optic material that propagates an optical signal along a first direction of propagation. An electrical waveguide is formed on the electro-optic material and positioned generally co-linear relative to the optical waveguide and in electromagnetic communication with the optical waveguide. The geometry of the electrical waveguide is selected to achieve a modulation efficiency at a frequency in a bandwidth of a digital spectrum. A compensation network is electrically coupled to the electrical waveguide at a junction. The compensation network reduces an electro-optic response of the electro-optic modulator below the mean frequency bandwidth of the digital spectrum, thereby causing an increase of the electro-optic response above the mean frequency of the digital spectrum.

Abstract: An apparatus and method for cleaving optical waveguides to precise differential length are described. A first end of a waveguide is coupled to an input port of a reflectometer. A reference mirror is then positioned in a path of radiation propagating through the second end of the waveguide. A waveguide cutting tool is then positioned proximate to the waveguide and at a distance relative to a reference mirror. A first reflectometry measurement is performed on the waveguide to a second end of the waveguide. A second reflectometry measurement is performed on the waveguide to the reference mirror. The waveguide is then positioned relative to the reference mirror and waveguide cutting tool so that the first reflectometery measurement is a measurement increment apart from the second reflectometry measurement. The waveguide is then cut with the cutting tool positioned at the distance relative to the reference mirror.