An apparatus for igniting a combustible mixture. In one example, the apparatus can include a coaxial cavity resonator assembly in a combustion environment. The apparatus can also include an operational feedback system and a controller. The operational feedback system can measure at least one of a voltage value and a current value of the coaxial cavity resonator assembly in the combustion environment. The controller can be configured to determine a condition of the coaxial cavity resonator assembly and modulate operation of the coaxial cavity resonator assembly based at least in part on the determined condition.

A method of providing spark ignition for an engine or other equipment having a combustion chamber. A radio frequency wave or a microwave (RF/microwave) generator delivers radio frequency waves or microwaves to a transmit antenna inside the combustion chamber. At least one RF/microwave receive antenna is attached to an internal surface of the combustion chamber and comprises two or more RF/microwave focusing features with a spark gap between them. The transmit antenna wirelessly energizes the receive antenna, which generates a spark between the two focusing features.

An igniter system and method for igniting a propellant by an optical energy source. The igniter system including an igniter composite and a propellant. The igniter composite including a reactive component and a fluoropolymer. The propellant is coupled to the igniter composite. The igniter composite has a composition including nano-aluminum at ideal stoichiometry in polyvinylidene fluoride. The igniter composite is configured to achieve a sustained ignition from a wavelength emitted from the optical energy source. The wavelength is between around 250 nanometers to around 1100 nanometers.

An igniter system and method for igniting a propellant by an optical energy source. The igniter system including an igniter composite and a propellant. The igniter composite including a reactive component and a fluoropolymer. The propellant is coupled to the igniter composite. The igniter composite has a composition including nano-aluminum at ideal stoichiometry in polyvinylidene fluoride. The igniter composite is configured to achieve a sustained ignition from a wavelength emitted from the optical energy source. The wavelength is between around 250 nanometers to around 1100 nanometers.

A method of providing spark ignition for an engine or other equipment having a combustion chamber. A radio frequency wave or a microwave (RF/microwave) generator delivers radio frequency waves or microwaves to a transmit antenna inside the combustion chamber. At least one RF/microwave receive antenna is attached to an internal surface of the combustion chamber and comprises two or more RF/microwave focusing features with a spark gap between them. The transmit antenna wirelessly energizes the receive antenna, which generates a spark between the two focusing features.

This disclosure presents, in one or more embodiments, an ignition device for a gasoline compression ignition engine. The ignition device includes a shuttle plunger with a gas chamber. The gas chamber is delimited by at least one sidewall of the shuttle plunger and captures exhaust gases. The ignition device also includes an electromagnetic coil that actuates the shuttle plunger in a first direction, a main body with a cavity containing the shuttle plunger and the electromagnetic coil, and a center electrode, fixed to the shuttle plunger, that ignites a fuel mixture.

This disclosure presents, in one or more embodiments, an ignition device for a gasoline compression ignition engine. The ignition device includes a shuttle plunger with a gas chamber. The gas chamber is delimited by at least one sidewall of the shuttle plunger and captures exhaust gases. The ignition device also includes an electromagnetic coil that actuates the shuttle plunger in a first direction, a main body with a cavity containing the shuttle plunger and the electromagnetic coil, and a center electrode, fixed to the shuttle plunger, that ignites a fuel mixture.

An ignition circuit and a method of operating an igniter (preferably a traveling spark igniter) in an internal combustion engine, including a high pressure engine. A high voltage is applied to electrodes of the igniter, sufficient to cause breakdown to occur between the electrodes, resulting in a high current electrical discharge in the igniter, over a surface of an isolator between the electrodes, and formation of a plasma kernel in a fuel-air mixture adjacent said surface. Following breakdown, a sequence of one or more lower voltage and lower current pulses is applied to said electrodes, with a low “simmer” current being sustained through the plasma between pulses, preventing total plasma recombination and allowing the plasma kernel to move toward a free end of the electrodes with each pulse.

An ignition circuit and a method of operating an igniter (preferably a traveling spark igniter) in an internal combustion engine, including a high pressure engine. A high voltage is applied to electrodes of the igniter, sufficient to cause breakdown to occur between the electrodes, resulting in a high current electrical discharge in the igniter, over a surface of an isolator between the electrodes, and formation of a plasma kernel in a fuel-air mixture adjacent said surface. Following breakdown, a sequence of one or more lower voltage and lower current pulses is applied to said electrodes, with a low “simmer” current being sustained through the plasma between pulses, preventing total plasma recombination and allowing the plasma kernel to move toward a free end of the electrodes with each pulse.

An optical oscillator includes a first reflection part configured to reflect light of a first wavelength, a laser medium excited by excitation light of a second wavelength different from the first wavelength and configured to emit light of the first wavelength, a second reflection part configured to form an unstable resonator together with the first reflection part, the unstable resonator being configured to output annular laser light of the first wavelength, and a saturable absorption part disposed between the laser medium and the second reflection part and of which a transmittance increases with absorption of light of the first wavelength. When a power of the excitation light is indicated by P.sub.p (kW), and an inner diameter of the annular laser light is indicated by d.sub.i, and an outer diameter is indicated by d.sub.o, and d.sub.o/d.sub.i is a magnification m, the magnification m satisfies a.sub.0+a.sub.1 Log(P.sub.p)≤m≤b.sub.0+b.sub.1P.sub.p+b.sub.2P.sub.p.sup.2.