Abstract: An ultraviolet light source includes a volume filled with a dose of AlCl.sub.3 and an inert gas. No mercury is used. During electrical discharge excited states of AlCl.sub.3, AlCl.sub.2, and AlCl emit light, with AlCl having a broad ultraviolet emission peaking at about 261.4 nm. The source may be energized with or without internal electrode. Phosphors may be employed to convert the ultraviolet to visible light. The lamp's envelope may be aluminosilicate coated quartz.

Abstract: A miniaturized vapor discharge lamp assembly that includes a light transmissive bulb containing a buffer gas and a vaporizable light radiating substance such as rubidium. Lamp excitation is provided by the use of a capacitor in the lamp assembly in conjunction with an RF oscillator. The capacitor establishes a substantially longitudinal electric field which ionizes the rubidium vapor to cause emission of light. The need for an RF excitation coil is eliminated.

Abstract: A compact fluorescent lamp has an outer envelope in which there is supported a capsule containing a mercury-free fill comprised of aluminum trichloride. The fill is energized to produce a plasma discharge which emits ultraviolet and visible radiation. Phosphor, in the form of a particulate layer or a gas, converts the ultraviolet into visible light. The lamp may contain electrodes or be electrodeless. In the electrodeless embodiment RF energy may be capacitively or inductively coupled to the fill.

Abstract: An improved oscillator circuit primarily for use as an RF source circuit for igniting a light discharge in a rubidium lamp used in a rubidium vapor cell frequency standard. A number of novel features are disclosed including an adjustable power capability dependent on current sensed feedback providing power adjustment over at least a 5-to-1 ratio; lamp heater monitoring for high oscillator power operation during warm-up; and light intensity monitoring for feedback bypass and high oscillator power operation whenever inadequate light discharge is detected.

Abstract: A resonance lamp of improved efficiency and stability is provided, using radio frequency excitation applied axially of the lamp, which is matched to the radio frequency source by making it part of an initially high Q tuned circuit resonant at the source frequency. This resonance promotes starting of the lamp, while the damping applied by the lamp circuit during running provides stabilization. A feedback circuit sensing lamp current or light output from a rare gas filling of the lamp provides longer term stability. The lamp may include a heated side arm containing a source of molecular gas which can be excited to provide radiation from an atomic species of interest, and the heating of the side arm is controlled not only by feedback from a temperature sensor but also by feedback from an optical detector sensitive to the radiation of interest.

Abstract: An improved laser power supply is disclosed. The invention is designed to provide the high electric field required for starting a laser in addition to the capability of automatically readjusting after laser action is initiated to provide an optimum impedance match for high efficiency energy transfer. The invention includes variable means for matching the impedance of a laser cavity with a source of RF energy. In addition, means are provided for sensing a change in the impedance of the laser cavity. The sensed change is then utilized to vary the impedance of the matching elements to provide and maintain an optimal coupling between the laser cavity and the RF source.

Abstract: In an electrodeless discharge lamp of the type including an ionizable medium within a sealed envelope capable of emitting radiant energy when subjected to a radio frequency field, an oscillator for generating an output signal at a given radio frequency of 13.56 MHz, an RF amplifier responsive to the oscillator output signal, and an induction coil and a capacitor connected in series and responsive to the output of the amplifier, the coil being positioned in close physical proximity to the medium in the envelope for coupling to the medium an electric field having a magnitude sufficient to initiate ionization of the medium and a magnetic field for maintaining ionization, there is disclosed an improvement wherein a Class D amplifier drives the series connected coil and capacitor without a separate load circuit connected in the output circuit of the amplifier. A specially selected filter and matching network coupled between the Class D amplifier and the series connected coil and capacitor reduces CV.sup.

Abstract: A method and apparatus for igniting a microwave generated discharge lamp. An ultraviolet-producing means is positioned so as to irradiate the fill-containing envelope of the discharge lamp. The ultraviolet-producing means is excited by microwave energy which is extracted from means which couples microwave energy from the microwave source to the fill-containing envelope of the discharge lamp.

Abstract: High-frequency electrodeless discharge device is operated by radio-frequency energy generated by an oscillator operating in Class E mode. By proper selection of the oscillator circuit components, a load-network capacitor can be eliminated along with an inductor which is normally required to pass direct current to the transistor switch portion of the oscillator. The elimination of these elements permits the oscillator to be packaged in compact fashion. The discharge device incorporates a looped core of high permeability material which forms a part of the tuned circuit output portion of the oscillator and the radio frequency energy electromagnetic fields passed through and about the core and within the envelope of the device excite a discharge-sustaining medium to generate plasma which is converted to visible radiations.

Abstract: A spectral source comprises a lamp containing an anode and a cathode in an inert gas. The anode and cathode are different in shape and connected to a high-frequency power source to produce a high-frequency discharge between the anode and cathode to cause both sputtering of the cathode and excitation of a radiation having the spectrum according to the material sputtered from the cathode. The application of solely high-frequency power prevents adherence of the sputtered material to the interior walls of the lamp bulb thereby allowing a reduction of the dimensions of the lamp bulb, prolongating the life time of the lamp and increasing the stability and intensity of the radiation. A magnetic field may be applied to the radiation for Zeeman modulation. Due to the relatively small dimensions of the lamp bulb, relatively small and inexpensive magnets may be used.

Abstract: A compact fluorescent lamp with a screw-in plug to fit conventional screw sockets which operates at 20-30 watts and provides the lumen output of a 75-100 watt lamp. The lamp is essentially a hollow cylinder with a glass envelope for the two outer walls. The space between the two outer walls is partitioned to constrain the arc discharge to follow a zigzag path around the surface of the lamp. The design parameters are such that the lumen output per square inch of phosphor is greater than from conventional tubular fluorescents. Efficiency is promoted by novel ballast design. The ballast fits into the hollow center of the lamp. The ballast is constructed of special shape to spread the arc within the evacuated glass envelope, thus reducing the current density and the total current, but maintaining the lumen output of the phosphor.

Abstract: Apparatus and process for reducing the rate of erosion of electrodes between which an arc is sustained by the provision of a field coil around the electrode which is supplied with direct current and the oscillation of that direct current supply at a frequency in the range 5.times.10.sup.-1 to 1.times.10.sup.-4 Hz.

Abstract: A method and apparatus for providing a completely closed plasma trap in an r.f. type glow discharge system to enable enhanced sputtering from a pair of electrodes so that substrates may be suitably coated. The electrode pairs may be post type, hollow or planar, in various shapes with and without end wings. All configurations utilize a cooperating magnetic field, provided by field coils external or internal to the electrodes, the magnetic field being shaped to define with the electrodes at least one plasma containing trap having axial symmetry imposed by the magnetic field and/or the electrode structure. The trap may be defined by the pair of electrodes acting in concert with each other and the magnetic field, one or more traps may be defined separately by each electrode and the magnetic field, or both types of traps may exist simultaneously in a hybrid situation. Means are also disclosed for mounting, centering, cooling, assembling and making electrical contact with various of the electrode structures.

Abstract: A method and apparatus for providing a completely closed plasma trap in an r.f. type glow discharge system to enable enhanced sputtering from a pair of electrodes so that substrates may be suitably coated. The electrode pairs may be post type, hollow or planar, in various shapes with and without end wings. All configurations utilize a cooperating magnetic field, provided by field coils external or internal to the electrodes, the magnetic field being shaped to define with the electrodes at least one plasma containing trap having axial symmetry imposed by the magnetic field and/or the electrode structure. The trap may be defined by the pair of electrodes acting in concert with each other and the magnetic field, one or more traps may be defined separately by each electrode and the magnetic field, or both types of traps may exist simultaneously in a hybrid situation. Means are also disclosed for mounting, centering, cooling, assembling and making electrical contact with various of the electrode structures.

Abstract: A solid state microwave power source for providing microwave power to excite an electrodeless lamp is designed so as to provide an acceptable impedance matching characteristic during lamp warm-up when the lamp impedance is high and changing with temperature to provide sufficient power to the lamp during the running state when the lamp impedance is matched to the source. The microwave power source includes a dc power source providing power at variable levels, a microwave oscillator receiving the dc power to produce a microwave signal, and a microwave power amplifier. The oscillator has a transistor in a common base configuration, a microstrip capacitive feedback element to sustain oscillations, and an output impedance matching arrangement formed from microstrip. The microwave signal is amplified in the solid state power amplifier having a power transistor in a common base configuration.

Abstract: Improved efficacy is obtained in an electrodeless light source of the type having a high frequency electrodeless lamp disposed at the ends of inner and outer conductors of a termination fixture by evacuating the region between the lamp envelope and the outer conductor to reduce conductive and convective heat losses.

Abstract: A discharge lamp with minimized upward bowing of the arc in which conductors carrying full arc current are placed in close proximity above and below the arc tube. The conductors run parallel with the longitudinal axis of the arc tube and the conductors above the arc are electrically connected in such a manner as to carry full lamp current in the opposite direction of the arc, thus repelling the arc in a downward direction, and the conductor or conductors below the arc tube are electrically connected so as to carry full lamp current in the same direction of the arc, thus attracting the arc downward.

Abstract: A half wavelength resonant cavity having inner and outer coaxial conductors is coupled at one end to a dc power source, and a gas discharge electrodeless lamp is disposed in the region between the conductors at the other end of the cavity. Repetitive bursts of radio frequency oscillations occur within the cavity, the oscillations causing breakdown of the fill material within the lamp to produce light.

Abstract: A starting assist control circuit for an electrodeless light source in which a UV source for assisting in starting an electrodeless lamp is coupled in series with the DC supply for a microwave power source for the lamp so that a reduced DC voltage is supplied to the microwave power source at lamp starting. An electronic circuit is provided which continuously decreases the DC current through the UV source and increases the DC voltage for the microwave power source in relation to the amount of light generated by the electrodeless lamp. More specifically, the emitter and collector of a transistor are coupled across the UV source to provide a shunt path and the potential of the base of the transistor is controlled by a photosensitive resistor which senses the amount of light from the lamp. As the lamp generates increased light, the transistor becomes more conductive, thereby continuously decreasing current to the UV source and increasing voltage to the microwave power source.

Abstract: A power supply circuit having a crystal controlled solid state oscillator induction coupled to a dual transistor circuit so as to eliminate second harmonics in a coil connected thereto and to a power supply in completing the circuit, and coil further having a resonance circuit therearound. Such power supply being suitable for driving a plasma gas envelope.

Abstract: A starting assist control circuit for an electrodeless light source in which a UV source for assisting in starting an electrodeless lamp is coupled in series with the dc supply for a microwave power source for the lamp so that a reduced dc voltage is supplied to the microwave power source at lamp starting. At staring, a capacitive impedance element is coupled across the inner and outer conductors of the fixture to provide an additional starting assist by creating a condition of resonance in the fixture. A heat responsive bimetallic switch element associated with both the capacitor and the UV source automatically shorts out the UV source and decouples the capacitor after the lamp has started thereby permitting full dc power to the microwave power source during the operating condition of the lamp.

Abstract: A method and apparatus for providing a completely closed plasma trap in an r.f. type glow discharge system to enable enhanced sputtering from a pair of electrodes so that substrates may be suitably coated. The electrode pairs may be post type, hollow or planar, in various shapes with and without end wings. All configurations utilize a cooperating magnetic field, provided by field coils external or internal to the electrodes, the magnetic field being shaped to define with the electrodes at least one plasma containing trap having axial symmetry imposed by the magnetic field and/or the electrode structure. The trap may be defined by the pair of electrodes acting in concert with each other and the magnetic field, one or more traps may be defined separately by each electrode and the magnetic field, or both types of traps may exist simultaneously in a hybrid situation. Means are also disclosed for mounting, centering, cooling, assembling and making electrical contact with various of the electrode structures.

Abstract: Three electrodes define two gaps in the crossed-field tube so that while one gap is holding off high voltage the other can be ignited to turn the tube on with high voltage applied. The three electrodes act as anode, cathode and control electrodes and define the main and ignition gaps. The intermediate electrode is gridded and the control electrode is connected to one of the other electrodes through an impedance to prevent hollow cathode discharge.

Abstract: In addition to the anode and cathode electrodes which define a low pressure gas filled main gap therebetween and a magnetic field to lengthen the electron path, the crossed-field switch device has a control electrode defining a second gas filled control gap in communication with the first, main conducting gap. An auxiliary voltage supply can be connected to the control gap to ignite a low pressure discharge, and the ionized plasma of this discharge leaks into the first gap to start a discharge in the glow mode.

Abstract: A central portion of the lamp is ionized by a RF field applied between two auxiliary electrodes and the strength of the RF signal resulting between the terminal electrodes of the lamp is measured as an indication of the fill gas pressure.

Abstract: An electrodeless fluorescent lamp adapted for economical substitution in place of existing incandescent lamps comprises an ionizable medium contained within a phosphor coated globular envelope. A closed loop, magnetic core, which may be ferrite, is contained within the ionizable medium to induce an electric field, ionize the medium, and stimulate visible light output. The core, which may be coated with glassy material, is energized by a radio frequency power source in the lamp base structure. Current from the power supply is transmitted to the core by means of a metal rod structure which also serves to transfer heat from within the envelope. A secondary winding on the core provides high starting voltages to initiate a glow discharge.

Abstract: An electrodeless discharge lamp has an ionizable medium comprising a particular gas composition at a particular pressure within a sealed envelope. Radio frequency electrical power is applied to an induction coil, the magnetic induction field of which is coupled to the medium. For a particular radio frequency, the magnitude of the induction field is selected to maximize the light emitted by the discharge per watt of radio frequency power coupled thereto. The radio frequency is preferably between 3 megahertz and 300 megahertz.

Abstract: An electrodeless fluorescent lamp adapted for economical substitution in place of an existing incandescent lamp comprises an ionizable medium contained within a phosphor coated globular envelope. A closed loop magnetic core transformer, contained within a reentrant cavity in the base of the envelope, induces a radio frequency electric field which ionizes the medium to stimulate production of visible light output from the phosphor. A tubular extension of the envelope traverses the cavity, linking the core with a column of ionizable medium, to form a "secondary winding" on the transformer. A base assembly, attached to the envelope, supports a lamp plug for receipt of input energy. A radio frequency power supply, contained within the base assembly, provides electric current to a primary winding on the core.

Abstract: A light source includes a source of high frequency power, an electrodelsss lamp and a termination fixture for coupling power to the lamp, the fixture having an outer conductor and an inner conductor whose length is adjustable for providing dynamic matching of the impedance of the lamp during the operating mode to the output impedance of the source. Variations in the power level from the source, such as is desirable in providing lamp brightness selectivity, vary both the real and imaginary components of the lamp impedance, and corresponding adjustments of the inner conductor length provide a tuning technique to compensate for these variations.

Abstract: An electrodeless lamp is excited by high frequency power in a termination fixture having an inner and an outer conductor, the lamp being located in the high field region at the end of the conductors. A source of ultraviolet radiation is located near the lamp and is activated momentarily when the lamp is to be excited. The radiation assists in initiating breakdown and excitation of the fill material in the lamp.

Abstract: In a light source in which an electrodeless lamp is excited by high frequency power coupled into a lamp termination fixture having an inner and outer conductor, the fixture has a dynamically variable characteristic impedance, thereby facilitating dynamic matching of the variable impedance of the lamp during the lamp-off to lamp-run conditions to the output impedance of the power source. This feature is possible because the position of the inner conductor with respect to the outer conductor is controlled as a function of the heat generated within the fixture. The inner conductor is made of a conductive material having a non-uniform coefficient of thermal expansion. When the fixture is cold, the lamp and the lamp-coupled end of the inner conductor are substantially concentric to the outer conductor thereby creating a high characteristic impedance to match the high starting lamp impedance to the source impedance.

Abstract: A termination fixture for an electrodeless lamp has dimensions which match the output impedance of a coupled high frequency power source to the real impedance of the lamp when in a discharge condition. The fixture may consist of a pair of coaxial conductors, and the lamp forms the termination load for the ends of the conductors. The length of the conductors is such as to place the lamp one quarter wavelength from the opposite ends of the conductors. The diameters of the conductors are such as to produce a fixture characteristic impedance which matches the lamp impedance to the source output impedance.

Abstract: A low power, sealed, optically thin resonance lamp having a controllable chemical decomposition source of a triatomic gas and a chemical getter sink in a sealed RF excited discharge. The discharge occurs in a second, extremely pure gas which is present in great excess over the gas produced by chemical decomposition. Excitation of species whose emission is desired occurs by electron impact or energy transfer from the major species which are, in turn, excited by the electron impact.

Abstract: A resonance lamp having a controllable chemical decomposition source of a parent species and a chemical getter sink in a sealed RF excited discharge. The discharge occurs in a second, extremely pure gas which is present in great excess over the gas produced by chemical decomposition. Excitation of species whose emission is desired occurs by electron impact or energy transfer from the major species which are, in turn, excited by the electron impact.