Tunable spectral source

• US 6,485,150 B1
• Filed: 07/03/2001
• Issued: 11/26/2002
• Est. Priority Date: 07/03/2001
• Status: Expired due to Fees

• Current Assignee: The United States of America As Represented By The Secretary of Agriculture
• Original Assignee: the united states of america as represented by the secretary of the navy
• Inventors: Driggers, Ronald G., Bendall, Charles S., Burroughs, Ellis E. Jr., Williams, Donald N.
• Primary Examiner(s): SIKDER, MOHAMMAD YUNUS
• Application Number:
  US09/898,778
• Time in Patent Office: 511 Days
• Field of Search: 359/615, 359/361, 359/566, 359/831, 359/850, 359/857, 359/856, 359/861
• US Class Current: 359/615
• CPC Class Codes: G01J 2003/1282 Spectrum tailoring
• CPC Class Codes: G01J 2003/1286 Polychromator in general
• CPC Class Codes: G01J 3/04 Slit arrangements slit adjustment
• CPC Class Codes: G01J 3/10 Arrangements of light sources specially adapted for spectrometry or colorimetry
• CPC Class Codes: G01J 3/12 Generating the spectrum; Monochromators
• CPC Class Codes: G01J 3/14 using refracting elements, e.g. prisms G01J3/18, G01J3/26 take precedence prisms per se G02B5/04
• CPC Class Codes: G02B 27/1086 operating by diffraction only
• CPC Class Codes: G02B 27/126 The splitting element being a prism or prismatic array, including systems based on total internal reflection

Abstract

A tunable spectral source includes an enclosure having first and second apertures; an optical dispersive element positioned in the enclosure; and multiple pixel source elements that are individually controllable for selectively directing one or more broadband light signals through the first aperture to irradiate the optical dispersive element. Each of the broadband light signals irradiates the optical dispersive element at a unique angle of incidence. The optical dispersive element disperses the broadband light signals into spectral component signals at dispersion angles that are dependent upon the angle of incidence of each broadband light signal that irradiates the optical dispersive element. The portions of the spectral component signals that are emitted through the second aperture are determined by selecting one or more particular pixel source elements to irradiate the optical dispersive element.

Claims

1. A tunable spectral source, comprising:

multiple pixel source elements for emitting broadband light signals;

an enclosure having a first aperture and a second aperture;

a first mirror mounted in said enclosure for receiving and collimating said broadband light signals received through said first aperture;

an optically diffractive element mounted in said enclosure for receiving said broadband light signals from said first mirror and diffracting said broadband light signals into spectral component signals; and

a second mirror mounted in said enclosure for directing said spectral component signals received from said optically diffractive element so that selected ones of said spectral component signals are emitted from said second aperture based on which of said pixel source elements generate said broadband light signals.

2. The tunable spectral source of claim 1 further including a processor for directing one or more of said multiple pixel source elements to emit said broadband light signals.

3. The tunable spectral source of claim 1 wherein said optically diffractive element is a diffraction grating.

4. The tunable spectral source of claim 1 wherein said broadband light signals each are white light signals.

5. The tunable spectral source of claim 1 wherein said spectral component signals are in bands ranging from long infrared to ultraviolet light.

6. The tunable spectral source of claim 1 further including a first lens for focusing said broadband light signals on a focal plane.

7. The tunable spectral source of claim 1 wherein each of said broadband light signals irradiates said optically diffractive element at a unique angle of incidence that determines which of said spectral component signals are emitted through said second aperture.