Patent US4713820A successfully refreshed from Google Patents.
US4713820A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Thermal lensing-compensated lanthanum beryllate laser
Assignee: Honeywell International Inc
•
Filing: 1985-08-02
•
Granted: 1987-12-15
•
Expires: 2005-08-02
Abstract
Abstract A single crystal of rare-earth-doped lanthanum beryllate, whose crystal orientation is suitably chosen, provides a laser medium whose index of refraction is substantially independent of temperature. A laser using such a crystal as the laser medium displays little or no thermal lensing, thus permitting high power operation without wavefront distortion.
Inventors
- 👤 Robert C. Morris
- 👤 Margaret N. Long
- 👤 Timothy C. Chin
- 👤 Donald F. Heller
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 16:30
CPC Classifications
H; H01; H01S; H01S3/00; H01S3/14; H01S3/16; C; C30; C30B; C30B15/00; C30B29/00; C30B29/10; C30B29/60; H01S3/05; H01S3/08; H01S3/08072; H01S3/163; H01S3/1663; H01S3/1665
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
80 words
A lanthanum beryllate single crystal that (a) is doped with an element selected from the group consisting of praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium and mixtures thereof; and (b) has an elongated shape, in which the long direction is oriented at such an angle with respect to the crystallographic axes of the crystal that a plane polarized wave propagating in the crystal in the long direction will have substantially zero temperature dependence of refractive index.
Claim 2
Dependent Claim
80 words
A lanthanum beryllate single crystal that (a) is doped with an element selected from the group consisting of praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium and mixtures thereof; and (b) has an elongated shape, in which the long direction is oriented at such an angle with respect to the crystallographic axes of the crystal that a plane polarized wave propagating in the crystal in the long direction will have substantially zero temperature dependence of refractive index.
Claim 3
Dependent Claim
17 words
The crystal of claim 1 in which the dopant comprises 0.1-10 atomic percent substitution for lanthanum sites.
Claim 4
Dependent Claim
11 words
The crystal of claim 1 in which the dopant is neodymium.
Claim 5
Dependent Claim
19 words
The crystal of claim 1 having a generally cylindrical shape, with the cylinder axis substantially along the long direction.
Claim 6
Dependent Claim
17 words
The crystal of claim 1 having the shape of an elongated slab with a substantially rectangular cross-section.
Claim 7
Dependent Claim
117 words
A laser that comprising: (a) a laser medium comprising a lanthanum beryllate single crystal that; (i) is doped with an element selected from the group consisting of praseodynium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulbium, ytterbium and mixtures thereof, and (ii) has an elongate shape, in which the long direction is oriented at such an angle with respect to the crystallographic axes of the crystal that a plane polarized wave propagating in the crystal in the long direction will have substantially zero temperature dependence of refractive index; (b) means for exciting the laser medium to emit a beam of coherent radiation; and (c) mirrors forming an optical resonator for maintaining laser oscillatios between the mirrors.
Claim 8
Dependent Claim
117 words
A laser that comprising: (a) a laser medium comprising a lanthanum beryllate single crystal that; (i) is doped with an element selected from the group consisting of praseodynium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulbium, ytterbium and mixtures thereof, and (ii) has an elongate shape, in which the long direction is oriented at such an angle with respect to the crystallographic axes of the crystal that a plane polarized wave propagating in the crystal in the long direction will have substantially zero temperature dependence of refractive index; (b) means for exciting the laser medium to emit a beam of coherent radiation; and (c) mirrors forming an optical resonator for maintaining laser oscillatios between the mirrors.
Claim 9
Dependent Claim
13 words
The laser of claim 6 further comprising a polarizer in the beam path.
Claim 10
Dependent Claim
22 words
The laser of claim 6 in which the laser medium has the shape of an elongated slab with a substantially rectangular cross-section.
Claim 11
Dependent Claim
37 words
The laser of claim 8 further comprising cooling means for providing a temperature gradient only in a direction in the slab that is normal to the direction along which exists the maximum temperature dependence of refractive index.
Claim 12
Dependent Claim
81 words
A lithium yttrium fluoride single crystal that (a) is doped with an element selected from the group consisting of praseodymium, neodymium, samarium, terbium, dysprosium, holmium, europium, gadolinium erbium, thulium, ytterbium and mixtures thereof; and (b) has an elongated shape, in which the long direction is oriented at such an angle with respect to the crystallographic axes of the crystal that a plane polarized wave propagating in the crystal in the long direction will have substantially zero temperature dependence of refractive index.
Claim 13
Dependent Claim
81 words
A lithium yttrium fluoride single crystal that (a) is doped with an element selected from the group consisting of praseodymium, neodymium, samarium, terbium, dysprosium, holmium, europium, gadolinium erbium, thulium, ytterbium and mixtures thereof; and (b) has an elongated shape, in which the long direction is oriented at such an angle with respect to the crystallographic axes of the crystal that a plane polarized wave propagating in the crystal in the long direction will have substantially zero temperature dependence of refractive index.
Claim 14
Dependent Claim
117 words
A laser that comprising: (a) a closer medium comprising a lithium ytrium fluoride single crystal that; (i) is doped with an element selected from the group consisting of praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium and mixtures thereof, (ii) has an elongated shape, in which the long direction is oriented at such an angle with respect to the crystallographic axes of the crystal that a plane polarized wave propagating in the crystal in the long direction will have substantially zero temperature dependence of refractive index; (b) means for exciting the laser medium to emit a beam of coherent radiation; and (c) mirrors forming an optical resonator for maintaining laser oscillations between the mirrors.
Claim 15
Dependent Claim
117 words
A laser that comprising: (a) a closer medium comprising a lithium ytrium fluoride single crystal that; (i) is doped with an element selected from the group consisting of praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium and mixtures thereof, (ii) has an elongated shape, in which the long direction is oriented at such an angle with respect to the crystallographic axes of the crystal that a plane polarized wave propagating in the crystal in the long direction will have substantially zero temperature dependence of refractive index; (b) means for exciting the laser medium to emit a beam of coherent radiation; and (c) mirrors forming an optical resonator for maintaining laser oscillations between the mirrors.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-12-14 | 1991-06-15 | 1991-12-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-12-14 | 1995-06-15 | 1995-12-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-12-14 | 1999-06-15 | 1999-12-15 | $7700.00 | Window Closed / Lapsed |