High frequency excited electrodeless light source

Claim 2

A light source including: a. a source of power at a high frequency, b. an electrodeless lamp having an envelope made of a light transmitting material and a volatile fill material disposed within the envelope, the fill material emitting light upon vaporization, partial ionization and excitation, and c. a termination fixture coupled to the source, the fixture including an inner conductor and an outer conductor disposed around and insulated from the inner conductor, the conductors having dimensions such that the lamp may be located in the high field region at the ends of the inner and outer conductors to form a lossy open circuit termination for the high frequency power which when applied initiates breakdown, vaporization and excitation of the fill material within the lamp.

Claim 3

The light source according to claim 1 further including means for matching the lamp impedance during the running state to the source impedance to enable maximum power transfer from the source to the lamp.

Claim 4

The light source according to claim 2 wherein the conductors have dimensions such that the fixture has a characteristic impedance which is equal to the impedance of the power source and wherein the matching means includes an impedance matching network disposed between the source and the lamp for matching the running lamp impedance to the source impedance.

Claim 5

The light source according to claim 3 wherein the conductors are concentric and circular in cross-section and wherein the ratio of the outer diameter of the inner conductor to the inner diameter of the outer conductor is constant at each location along a longitudinal axis of the fixture.

Claim 6

The light source according to claim 4 further including a transmission line coupling high frequency power from the source to the fixture, the characteristic impedance of the fixture being equal to the characteristic impedance of the line.

Claim 7

The light source according to claim 5 wherein the characteristic impedance of the line is 50 ohms and the ratio of conductor diameters is approximately 2.3.

Claim 8

The light source according to claim 5 wherein the impedance matching network is a stub stretcher disposed along the transmission line.

Claim 9

The light source according to claim 1 wherein the inner and outer conductors are plated with a highly conductive metal to reduce skin depth losses.

Claim 10

The light source according to claim 8 wherein the plated conductors are polished to enhance the intensity of illumination from the fixture.

Claim 11

The light source according to claim 1 further including means for holding the lamp in place on the end of the inner conductor.

Claim 12

The light source according to claim 1 wherein the high frequency is within the ISM frequency bands.

Claim 13

The light source according to claim 11 wherein the frequency is 915 MHz.

Claim 14

The light source according to claim 1 wherein the fill material is adapted to produce a high pressure discharge upon excitation.

Claim 15

The light source according to claim 13 wherein the lamp fill material is mercury and argon and the envelope is spherical in shape and made of quartz.

Claim 16

A light source including: a. a source of power at a high frequency, b. an electrodeless lamp having an envelope made of a light transmitting material and a volatile fill material disposed within the envelope, the fill material emitting light upon vaporization, partial ionization and excitation, and c. a termination fixture coupled to the source, the fixture including an inner conductor and an outer conductor disposed around the inner conductor, the conductors having dimensions such that the lamp may be located in the high field region at the ends of the inner and outer conductors to form a lossy open circuit termination for the high frequency power which when applied initiates breakdown, vaporization and excitation of the fill material within the lamp, the conductors having dimensions such that the fixture has a characteristic impedance which is equal to the impedance of the power source and being concentric and circular in cross-section, the ratio of the outer diameter of the inner conductor to the inner diameter of the outer conductor being constant at each location along a longitudinal axis of the fixture, the diameters of the inner and outer conductors increasing along the longitudinal axis in a direction toward the lamp, and d. means for matching the lamp impedance during the running state to the source impedance to enable maximum power transfer from the source to the lamp, the matching means including an impedance matching network disposed between the source and the lamp for matching the running lamp impedance to the source impedance.

Claim 17

A light source including: a. a source of power at a high frequency, b. an electrodeless lamp having an envelope made of a light transmitting material and a volatile fill material disposed within the envelope, the fill material emitting light upon vaporization, partial ionization and excitation, and c. a termination fixture coupled to the source, the fixture including an inner conductor and an outer conductor disposed around the inner conductor, the conductors having dimensions such that the lamp may be located in the high field region at the ends of the inner and outer conductors to form a lossy open circuit termination for the high frequency power which when applied initiates breakdown, vaporization and excitation of the fill material within the lamp, the conductors having dimensions such that the fixture has a characteristic impedance which is equal to the impedance of the power source and being concentric and circular in cross-section, the ratio of the outer diameter of the inner conductor to the inner diameter of the outer conductor being constant at each location along a longitudinal axis of the fixture, the diameters of the inner and outer conductors increasing along the longitudinal axis in a direction toward the lamp, and d. means for matching the lamp impedance during the running state to the source impedance to enable maximum power transfer from the source to the lamp, the matching means including an impedance matching network disposed between the source and the lamp for matching the running lamp impedance to the source impedance.

Claim 18

The light source according to claim 15, wherein the length of the outer conductor projected along the longitudinal axis is at least equal to the length of the inner conductor plus the diameter of the lamp envelope.

Claim 19

A light source including: a. a source of power at a high frequency, b. an electrodeless lamp having an envelope made of a light transmitting material and a volatile fill material disposed within the envelope, the fill material emitting light upon vaporization, partial ionization and excitation, and c. a termination fixture coupled to the source, the fixture including an inner conductor and an outer conductor disposed around the inner conductor, the conductors having dimensions such that the lamp may be located in the high field region at the ends of the inner and outer conductors to form a lossy open circuit termination for the high frequency power which when applied initiates breakdown, vaporization and excitation of the fill material within the lamp, the end of the inner conductor being formed with a central circular depressed region having a maximum diameter less than that of the lamp, the lamp being disposed over the opening of the region to minimize the transfer of heat from the lamp to the inner conductor.

Claim 20

A light source including: a. a source of power at a high frequency, b. an electrodeless lamp having an envelope made of a light transmitting material and a volatile fill material disposed within the envelope, the fill material emitting light upon vaporization, partial ionization and excitation, and c. a termination fixture coupled to the source, the fixture including an inner conductor and an outer conductor disposed around the inner conductor, the conductors having dimensions such that the lamp may be located in the high field region at the ends of the inner and outer conductors to form a lossy open circuit termination for the high frequency power which when applied initiates breakdown, vaporization and excitation of the fill material within the lamp, the end of the inner conductor being formed with a central circular depressed region having a maximum diameter less than that of the lamp, the lamp being disposed over the opening of the region to minimize the transfer of heat from the lamp to the inner conductor.

Claim 21

A light source including: a. a source of power at a high frequency, b. an electrodeless lamp having an envelope made of a light transmitting material and a volatile fill material disposed within the envelope, the fill material emitting light upon vaporization, partial ionization and excitation, and c. a termination fixture coupled to the source, the fixture including an inner conductor and an outer conductor disposed around the inner conductor, the conductors having dimensions such that the lamp may be located in the high field region at the ends of the inner and outer conductors to form a lossy open circuit termination for the high frequency power which when applied initiates breakdown, vaporization and excitation of the fill material within the lamp, and d. a metallic screen being made of a highly conducting material and having a high optical transmission factor located over the opening in the outer conductor to contain stray radiation.

Claim 22

A light source including: a. a source of power at a high frequency, b. an electrodeless lamp having an envelope made of a light transmitting material and a volatile fill material disposed within the envelope, the fill material emitting light upon vaporization, partial ionization and excitation, and c. a termination fixture coupled to the source, the fixture including an inner conductor and an outer conductor disposed around the inner conductor, the conductors having dimensions such that the lamp may be located in the high field region at the ends of the inner and outer conductors to form a lossy open circuit termination for the high frequency power which when applied initiates breakdown, vaporization and excitation of the fill material within the lamp, and d. a metallic screen being made of a highly conducting material and having a high optical transmission factor located over the opening in the outer conductor to contain stray radiation.

Claim 23

The light source according to claim 18 wherein the screen is in contact with the lamp to secure the lamp in place at the end of the inner conductor.

Claim 24

A light source including: a. a source of power at a high frequency, b. an electrodeless lamp having an envelope made of a light transmitting material and a volatile fill material disposed within the envelope, the fill material emitting light upon vaporization, partial ionization and excitation, and c. a termination fixture coupled to the source, the fixture including an inner conductor and an outer conductor disposed around the inner conductor, the conductors having dimensions such that the lamp may be located in the high field region at the ends of the inner and outer conductors to form a lossy open circuit termination for the high frequency power which when applied initiates breakdown, vaporization and excitation of the fill material within the lamp, and d. means for holding the lamp in place on the end of the inner conductor, the lamp holding means including at least one rod connected to the outer conductor and contacting the lamp to secure the lamp between the inner conductor and the rod.

Claim 25

A light source including: a. a source of power at a high frequency, b. an electrodeless lamp having an envelope made of a light transmitting material and a volatile fill material disposed within the envelope, the fill material emitting light upon vaporization, partial ionization and excitation, and c. a termination fixture coupled to the source, the fixture including an inner conductor and an outer conductor disposed around the inner conductor, the conductors having dimensions such that the lamp may be located in the high field region at the ends of the inner and outer conductors to form a lossy open circuit termination for the high frequency power which when applied initiates breakdown, vaporization and excitation of the fill material within the lamp, and d. means for holding the lamp in place on the end of the inner conductor, the lamp holding means including at least one rod connected to the outer conductor and contacting the lamp to secure the lamp between the inner conductor and the rod.

Claim 26

The light source according to claim 20 wherein the rod is stainless steel and the conductors are brass.