Plasma light source, inspection apparatus including plasma light source, and method of generating plasma light

Patent metadata

Field	Value
Publication number	US-9305764-B2
Application number	US-201514613988-A
Country	US
Kind code	B2
Filing date	Feb 4, 2015
Priority date	Jul 1, 2014
Publication date	Apr 5, 2016
Grant date	Apr 5, 2016

Abstract

A plasma light source includes a chamber having an ionizable medium therein, an ignition source configured to provide first electromagnetic radiation to the chamber, a sustaining source configured to separately provide second electromagnetic radiation to the chamber, a first curved mirror positioned adjacent the chamber, and a second curved mirror positioned opposite the first mirror and arranged to direct the first electromagnetic radiation toward the chamber. The second electromagnetic radiation may be different than the first electromagnetic radiation. Related devices and methods of operation are also discussed.

First claim

That which is claimed:

1. A plasma light source comprising:
a chamber comprising an ionizable medium therein;
an ignition source configured to provide first electromagnetic radiation to the chamber;
a sustaining source configured to separately provide second electromagnetic radiation to the chamber;
a first curved mirror positioned adjacent the chamber; and
a second curved mirror positioned opposite the first mirror and arranged to direct the first electromagnetic radiation toward the chamber.

2. The plasma light source of claim 1 , wherein at least one of the first and second curved mirrors comprises a hybrid mirror including first and second layers having different refractive indices, at least one of the first and second layers being reflective with respect to the first electromagnetic radiation.

3. The plasma light source of claim 2 , wherein the first and second layers comprise inner and outer surfaces, respectively, comprising different materials and/or different curvatures.

4. The plasma light source of claim 3 , wherein the second layer is reflective to the first electromagnetic radiation, and wherein the first layer is reflective to light emitted from plasma ignited by the first electromagnetic radiation.

5. The plasma light source of claim 4 , wherein a focus of the second layer of the second curved mirror is on the second layer of the first curved mirror.

6. The plasma light source of claim 4 , wherein a focus of the first layer of the second curved mirror is not on the chamber.

7. The plasma light source of claim 4 , wherein a focus of the second layer of the respective first and second curved mirrors is on the chamber.

8. The plasma light source of claim 1 , further comprising:
at least one dichroic mirror that is reflective with respect to the second electromagnetic radiation, wherein the at least one dichroic mirror is positioned between the first and second curved mirrors and arranged to direct the second electromagnetic radiation to the first curved mirror.

9. The plasma light source of claim 8 , wherein the at least one dichroic mirror is transmissive with respect to the first electromagnetic radiation.

10. The plasma light source of claim 9 , wherein the at least one dichroic mirror comprises a first dichroic mirror, and further comprising:
a second dichroic mirror that is reflective with respect to the second electromagnetic radiation and is arranged to direct the second electromagnetic radiation to the first dichroic mirror.

11. The plasma light source of claim 1 , wherein a distance between the first and second curved mirrors defines a resonator based on a wavelength of the first electromagnetic radiation.

12. The plasma light source of claim 1 , wherein an outer surface of the first curved mirror is free of a metal coating.

13. The plasma light source of claim 1 , wherein the ignition source comprises a microwave generator configured to provide microwave energy as the first electromagnetic radiation, and further comprising:
a waveguide coupled to the microwave generator and configured to transmit the microwave energy from the microwave generator to the first curved mirror,
wherein the first curved mirror is reflective with respect to the microwave energy.

14. The plasma light source of claim 13 , wherein the waveguide is positioned at a non-zero angle relative to an axis of symmetry of the first curved mirror.

15. The plasma light source of claim 13 , wherein the sustaining source comprises a laser generator configured to provide laser energy as the second electromagnetic radiation, and wherein the second curved mirror includes a pin-hole aperture therein that is arranged to provide the laser energy from the sustaining source therethrough to the chamber.

16. The plasma light source of claim 15 , wherein a dimension of the pin-hole aperture is less than about one half of a wavelength of the microwave energy.

17. The plasma light source of claim 15 , further comprising a dichroic mirror that is reflective or transmissive to the laser energy, wherein the dichroic mirror is positioned adjacent the pin-hole aperture and is arranged to direct the laser energy therethrough to the chamber.

18. The plasma light source of claim 17 , wherein the dichroic mirror is further reflective or transmissive with respect to light emitted from plasma ignited by the microwave energy and is arranged to direct the light emitted from the plasma as an output of the plasma light source.

Assignees

• Park Young-Kyu
• Kim Wook-Rae
• Kim Kwang-Soo
• Kim Tae-Joong
• Jeon Byeong-Hwan
• Samsung Electronics Co Ltd

Inventors

• Park Young-Kyu
• Kim Wook-Rae
• Kim Kwang-Soo
• Kim Tae-Joong
• Jeon Byeong-Hwan

Classifications

• G02B27/141 Primary

  using dichroic mirrors · CPC title

• H01J65/044 Primary

  the field being produced by a separate microwave unit · CPC title

• G02B19/0028

  refractive and reflective surfaces, e.g. non-imaging catadioptric systems · CPC title

• H01J65/04

  Lamps in which a gas filling is excited to luminesce by an external electromagnetic field or by external corpuscular radiation, e.g. for indicating {plasma display panels} · CPC title

• G02B19/0047

  for use with a light source (G02B19/009, G02B19/0095 take precedence; details of lighting devices in general F21V; non-semiconductor lasers having optical devices external to the laser cavity H01S3/005) · CPC title