EP0408142A1
Expired / Lapsed
EP
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Method and electric circuit for exciting a gas discharge laser
Assignee: NEDERLANDS CENTRUM VOOR LASER RESEARCH BV
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Filing: 1990-07-10
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Granted: —
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Expires: 2010-07-10
Abstract
Abstract A method and a device are disclosed for exciting a gas discharge laser, wherein two capacitive energy storage circuits are coupled in parallel to the electrodes of a laser, wherein a first of said energy storage circuits serves to provide energy to the laser to sustain a discharge therein, and wherein a second of said energy storage circuits serves to provide energy to the laser to effect ignition of the discharge. Immediately prior to ignition, the polarity of the second energy storage circuit is opposite to the polarity of the first energy storage circuit. By resonantly transferring charge from the first energy storage circuit to the second energy storage circuit, the polarity of the second energy storage circuit is reversed and the voltage level of the second energy storage circuit is brought to a value suitable for igniting the laser by virtue of the overshoot effect.
Inventors
- 👤 Aart Louis Keet
- 👤 Jan Willem Gerritsen
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-03 19:50
CPC Classifications
H; H01; H01S; H01S3/00; H01S3/09; H01S3/097
Claims Analysis
Total Claims: 31
Claim 1
Independent Claim
189 words
A method of exciting a gas discharge laser comprising first and second electrodes having connected to them capacitive first and second electric energy storage circuits between which resonant charge transfer is possible; wherein an electric charge is provided to the first energy storage circuit resulting in a voltage with a first polarity relative to the electrodes of the laser; wherein electric charge is resonantly transferred from said first energy storage circuit to said second energy storage circuit for igniting the laser; and wherein sufficient electric energy is supplied from said first energy storage circuit for sustaining the laser in an ignited state for a certain period of time, characterized by the steps of: - supplying the second energy storage circuit with an electric charge, such that a voltage results with a second polarity relative to the electrodes of the laser, said second polarity being opposite to the first polarity; and - subsequently effecting a resonant charge exchange between the first and the second energy storage circuits, in such a way that the second energy storage circuit attains a voltage of the first polarity, sufficiently high for igniting the laser.
Claim 2
Independent Claim
189 words
A method of exciting a gas discharge laser comprising first and second electrodes having connected to them capacitive first and second electric energy storage circuits between which resonant charge transfer is possible; wherein an electric charge is provided to the first energy storage circuit resulting in a voltage with a first polarity relative to the electrodes of the laser; wherein electric charge is resonantly transferred from said first energy storage circuit to said second energy storage circuit for igniting the laser; and wherein sufficient electric energy is supplied from said first energy storage circuit for sustaining the laser in an ignited state for a certain period of time, characterized by the steps of: - supplying the second energy storage circuit with an electric charge, such that a voltage results with a second polarity relative to the electrodes of the laser, said second polarity being opposite to the first polarity; and - subsequently effecting a resonant charge exchange between the first and the second energy storage circuits, in such a way that the second energy storage circuit attains a voltage of the first polarity, sufficiently high for igniting the laser.
Claim 3
Dependent Claim
66 words
A method according to claim 1, characterized in that the step of supplying the second energy storage circuit with an electric charge comprises: - supplying the second energy storage circuit with an electric charge, resulting in a voltage with the first polarity , and - charge reversing the second energy storage circuit for effecting a state of charge resulting in a voltage with the second polarity.
Claim 4
Dependent Claim
20 words
A method according to claim 2, characterized in that the second energy storage circuit is resonantly charge reversed in itself.
Claim 5
Dependent Claim
29 words
A method according to claim 2, characterized in that the second energy storage circuit is charge reversed using a capacitive third energy storage circuit supplied with an electric charge.
Claim 6
Dependent Claim
18 words
A method according to claim 4, characterized in that the second energy storage circuit is resonantly charge reversed.
Claim 7
Independent Claim
70 words
A method according to any of the preceding claims, for exciting a gas discharge laser with an ignition voltage of the order of magnitude of twice the value of its discharge voltage, characterized in that the first and second energy storage circuits are supplied with electric charges, resulting in opposite polarized voltages relative to the electrodes of the laser with values of the order of magnitude of the discharge voltage.
Claim 8
Independent Claim
67 words
A method according to any of the claims 1-5, for exciting a gas discharge laser with an ignition voltage higher than twice the value of its discharge voltage, characterized in that the first and second energy storage circuits are supplied with electric charges, resulting in opposite polarized voltages relative to the electrodes of the laser with values of the order of magnitude of twice the discharge voltage.
Claim 9
Dependent Claim
67 words
A method according to claim 5, characterized in that the second and third energy storage circuits are supplied with electric charges, resulting in mutually opposite polarized voltages with values of the order of magnitude of the discharge voltage, in which the second energy storage circuit by resonant charge reversal is brought to a voltage with a value of the order of magnitude of twice the discharge voltage.
Claim 10
Independent Claim
21 words
A method according to any of the preceding claims, characterized in that the resonant charge transfer is effected using magnetic switches.
Claim 11
Independent Claim
25 words
A method according to any of the preceding claims, characterized in that the first energy storage circuit is a part of a pulse forming network.
Claim 12
Dependent Claim
136 words
An electric excitation circuit, suitable for carrying out the method according to one or more of the preceding claims, comprising: first and second load terminals for connecting an electric load; at least one capacitive first energy storage circuit with means for supplying electric charge to said at least one first energy storage circuit, resulting in a voltage with a first polarity relative to the load terminals, said first energy storage circuit being connected with the load terminals via a first inductive switching circuit; and at least one capacitive second energy storage circuit connected with the load terminals; characterized by further means for supplying electric charge to said at least one second energy storage circuit, resulting in a voltage with a second polarity relative to the load terminals, said second polarity being opposite to the first polarity.
Claim 13
Dependent Claim
46 words
An electric excitation circuit according to claim 11, characterized in that the further means comprise an inductive further switching circuit coupled to said at least one second energy storage circuit, for the resonant supply of electric charge to said at least one second energy storage circuit.
Claim 14
Dependent Claim
62 words
An electric excitation circuit according to claim 11, characterized in that one switching circuit is equipped for supplying electric charge from said at least one first energy storage circuit to said at least one second energy storage circuit, resulting in a voltage with the first polarity, the further means being equipped for charge reversing said at least one second energy storage circuit.
Claim 15
Dependent Claim
51 words
An electric excitation circuit according to claim 13, characterized in that the further means comprise an inductive further switching circuit coupled with said at least one second energy storage circuit, the switching of said further switching circuit permitting the resonant charge reversal of said at least one second energy storage circuit.
Claim 16
Dependent Claim
22 words
An electric excitation circuit according to claim 14, characterized in that the inductive further switching circuit comprises at least magnetically saturable coil.
Claim 17
Dependent Claim
73 words
An electric excitation circuit according to claim 13, characterized in that the further means comprise at least one capacitive third energy storage circuit, with yet further means for supplying electric charge to said at least one third energy storage circuit, and a yet further switching circuit coupled thereto, the switching of said switching circuit permitting the exchange of charge with said at least one second energy storage circuit for the charge reversal thereof.
Claim 18
Dependent Claim
41 words
An electric excitation circuit according to claim 16, characterized in that said at least one third energy storage circuit in series with its yet further inductive switching circuit is coupled in parallel with said at least one second energy storage circuit.
Claim 19
Dependent Claim
42 words
An electric excitation circuit according to claim 16, characterized in that said at least one third energy storage circuit in series with its yet further switching circuit is coupled in series with said at least one first and second energy storage circuits.
Claim 20
Dependent Claim
37 words
An electric excitation circuit according to claim 18, characterized in that said at least one third energy storage circuit in series with its yet further switching circuit is coupled in parallel with said one inductive switching circuit.
Claim 21
Dependent Claim
25 words
An electric excitation circuit according to any of claims 13-19, characterized in that said one inductive switching circuit comprises at least one magnetically saturable coil.
Claim 22
Dependent Claim
66 words
An electric excitation circuit according to claim 18, characterized in that said one inductive switching circuit comprises at least one magnetically saturable transformer, to the primary winding of which said at least one third energy storage circuit in series with its yet further switching circuit is connected, and the secondary winding of which is connected in series with said at least one first energy storage circuit.
Claim 23
Dependent Claim
29 words
An electric excitation circuit according to any of claims 15-19, characterized in that said yet further switching circuit is an inductive switching circuit for the resonant exchange of charge.
Claim 24
Dependent Claim
36 words
An electric excitation circuit according to any of claims 11-22, characterized in that said further and yet further switching circuits each comprise at least one series connection of a semiconductor switching element and an inductive element.
Claim 25
Dependent Claim
32 words
An electric excitation circuit according to any of claims 11-23, characterized in that said at least one first, second and third energy storage circuits comprise one or more elements with capacitive action.
Claim 26
Dependent Claim
35 words
An electric excitation circuit according to any of claims 11-24, characterized in that said at least one second energy storage circuit is coupled with the load terminals in a low-inductance manner as much as possible.
Claim 27
Dependent Claim
28 words
An electric excitation circuit according to any of claims 11-25, characterized in that said at least one first energy storage circuit is part of a pulse forming network.
Claim 28
Dependent Claim
38 words
An electric excitation circuit according to any of claims 11-26, characterized in that at least one power supply circuit is provided for optionally supplying electric charge to said at least one first, second, and third energy storage circuits.
Claim 29
Dependent Claim
28 words
An electric excitation circuit according to any of claims 11-27, characterized in that at least one gas discharge laser is connected to said first and second load terminals.
Claim 30
Dependent Claim
20 words
An electric excitation circuit according to claim 28, characterized in that said at least one laser is a CO₂ laser.
Claim 31
Dependent Claim
20 words
An electric excitation circuit according to claim 28, characterized in that said at least one laser is an excimer laser.
References Cited (Backward Citations)
US4679203A
Cited
WO1989010657A1
Cited
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