US5610734A
Expired / Lapsed
US
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Chromatic focal pencil beam-generating apparatus
Assignee: Leland Stanford Junior University
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Filing: 1995-02-09
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Granted: 1997-03-11
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Expires: 2015-02-09
Abstract
Abstract An optical system is disclosed which focuses a polychromatic source to an extended focal pencil. The implementation makes use of two holographic optical elements (HOEs) fabricated and aligned to form a deliberate longitudinal color dispersion, but to alleviate lateral chromatic effects. Consequently, the HOE doublet focuses different wavelengths of the source to different locations along the optical axis. The strong intensity of the focused wavelengths dominate at each location, so that the overall beam has a near-diffraction-limited 1/e2 spot size and suffers only relatively weak background illumination. An alternative optical system using bulk lenses and several possible applications for the device are also described.
Inventors
- 👤 Abraham Aharoni
- 👤 Joseph W. Goodman
- 👤 Yaakov Amitai
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 12:08
CPC Classifications
G; G02; G02B; G02B5/00; G02B5/32
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
122 words
A polychromatic focal pencil beam-generating apparatus comprising: a polychromatic light source for generating a beam of light having a polychromatic spectrum; and optical means including a first holographic optical element for collecting and collimating said beam of light, and a second holographic optical element antisymmetric to said first holographic optical element for focusing the collimated beam and for correcting lateral chromatic shift caused by said first holographic optical element, the resulting beam having substantial longitudinal chromatic dispersion and forming a pencil beam of light having a wavelength at one end of said polychromatic spectrum focused at a first point that is remote from a second point at which light having a wavelength at the opposite end of said polychromatic spectrum is focused.
Claim 2
Dependent Claim
122 words
A polychromatic focal pencil beam-generating apparatus comprising: a polychromatic light source for generating a beam of light having a polychromatic spectrum; and optical means including a first holographic optical element for collecting and collimating said beam of light, and a second holographic optical element antisymmetric to said first holographic optical element for focusing the collimated beam and for correcting lateral chromatic shift caused by said first holographic optical element, the resulting beam having substantial longitudinal chromatic dispersion and forming a pencil beam of light having a wavelength at one end of said polychromatic spectrum focused at a first point that is remote from a second point at which light having a wavelength at the opposite end of said polychromatic spectrum is focused.
Claim 3
Dependent Claim
19 words
A polychromatic focal pencil beam-generating apparatus as recited in claim 1 wherein said light source is a diode laser.
Claim 4
Dependent Claim
79 words
A polychromatic focal pencil beam-generating apparatus as recited in claim 1 and further comprising: beam-splitting means disposed along the optical axis between said source and said optical means; and light detector means for developing an electrical signal proportional to light directed thereupon, said beam-splitting means being operative to direct light reflected from a target and returned through said optical means onto said detector means, said apparatus being relatively insensitive to changes in separation between said apparatus and said target.
Claim 5
Dependent Claim
19 words
A polychromatic focal pencil beam-generating apparatus as recited in claim 3 wherein said light source is a diode laser.
Claim 6
Dependent Claim
86 words
A polychromatic focal pencil beam-generating apparatus as recited in claim 1 and further comprising: a beam-splitting means disposed between said first and second holographic optical elements; a detector array including a plurality of detector elements; and focusing means for focusing light reflected from an object and passed back through said second holographic optical element where it is directed by said beam-splitting means through said focusing means onto said array such that the position of said object determines the detector element upon which said light is focused.
Claim 7
Dependent Claim
19 words
A polychromatic focal pencil beam-generating apparatus as recited in claim 5 wherein said light source is a diode laser.
Claim 8
Dependent Claim
169 words
A polychromatic focal pencil beam-generating apparatus, comprising: a polychromatic light source for generating a beam of light having a polychromatic spectrum, said light source including a mode-selectable diode laser; optical means including a first holographic optical element for collecting and collimating said beam of light, and a second holographic optical element antisymmetric to and aligned relative to said first holographic optical element for correcting lateral chromatic shift caused by said first holographic optical element, the focused beam having substantial longitudinal chromatic dispersion whereby light having a wavelength at one end of said polychromatic spectrum is focused at a first point that is remote from a second point at which light having a wavelength at the opposite end of the polychromatic is focused; and a movable reflective target positioned along the optical axis of said optical means to reflect the focused beam back through said optical means to said laser to force the laser to lase in a mode determined by the wavelength focused at the position of said reflector.
Claim 9
Dependent Claim
169 words
A polychromatic focal pencil beam-generating apparatus, comprising: a polychromatic light source for generating a beam of light having a polychromatic spectrum, said light source including a mode-selectable diode laser; optical means including a first holographic optical element for collecting and collimating said beam of light, and a second holographic optical element antisymmetric to and aligned relative to said first holographic optical element for correcting lateral chromatic shift caused by said first holographic optical element, the focused beam having substantial longitudinal chromatic dispersion whereby light having a wavelength at one end of said polychromatic spectrum is focused at a first point that is remote from a second point at which light having a wavelength at the opposite end of the polychromatic is focused; and a movable reflective target positioned along the optical axis of said optical means to reflect the focused beam back through said optical means to said laser to force the laser to lase in a mode determined by the wavelength focused at the position of said reflector.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2000-03-10 | 2000-09-09 | 2001-03-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2004-03-10 | 2004-09-09 | 2005-03-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2008-03-10 | 2008-09-09 | 2009-03-11 | $7700.00 | Window Closed / Lapsed |