Heterogeneous single vanadate based crystals for Q-switched lasers and microlasers and method for forming same

Patent metadata

Field	Value
Publication number	US-9493887-B1
Application number	US-201414497949-A
Country	US
Kind code	B1
Filing date	Sep 26, 2014
Priority date	Jul 8, 2010
Publication date	Nov 15, 2016
Grant date	Nov 15, 2016

Abstract

Disclosed are heterogeneous crystals for use in a laser cavity and methods of forming the crystals. A crystal can be a monolithic crystal containing a vanadate-based activator region and a vanadate-based Q-switch. Disclosed methods include hydrothermal growth techniques for the growth of differing layers on a host. A YVO 4 host material can be doped in one region with a suitable active lasing ion and can be formed with another region that is doped with a saturable absorber. Regions can be formed with controlled thickness. Following formation, a heterogeneous crystal can be cut, polished and coated with mirror films at each end for use in a laser cavity to provide short pulses of high power emissions using high frequency pulse modes.

First claim

What is claimed is:

1. A method for forming a monolithic heterogeneous crystal comprising heating and pressurizing an aqueous solution held within a reactor to develop a temperature differential between a first zone of the reactor and a second zone of the reactor, the reactor containing a vanadate forming feedstock in the first zone and a vanadate seed crystal in the second zone, the feedstock forming the same vanadate as the vanadate of the seed crystal, the feedstock including a source for a saturable absorber ion, wherein upon said heating and pressurizing growth of a vanadate Q-switch crystal region is initiated on the vanadate seed crystal to form a monolithic vanadate product crystal, the composition of the Q-switch crystal region differing from the composition of the seed crystal such that the monolithic vanadate product crystal is heterogeneous.

2. The method according to claim 1 , the aqueous solution comprising a mineralizer.

3. The method according to claim 1 , wherein the vanadate is YVO 4 .

4. The method according to claim 1 , one of the vanadate seed crystal and the Q-switch crystal region comprising an active lasing ion dopant.

5. The method according to claim 4 , wherein one of the vanadate seed crystal and the Q-switch regions comprises an active lasing ion at a concentration of greater than about 2 at. % of the vanadate host material of that region.

6. The method according to claim 4 , wherein the active lasing ion is Nd 3+ or Yb 3+ .

7. The method according to claim 1 , the feedstock further comprising a source for an active lasing ion dopant.

8. The method according to claim 1 , the feedstock further comprising a source for an ion for balancing lattice charge of the Q-switch crystal region.

9. The method according to claim 1 , wherein the seed crystal is a heterogeneous monolithic crystal.

10. The method according to claim 1 , wherein the seed crystal comprises a region of the vanadate that is undoped.

11. The method according to claim 1 , wherein the reactor comprises an inert metal liner.

12. The method according to claim 1 , wherein the aqueous solution is pressurized to a pressure of between about 5 kpsi and about 30 kpsi.

13. The method according to claim 1 , wherein the temperature of the second zone is between about 450° C. and about 650° C.

14. The method according to claim 1 , wherein the temperature difference is between about 20° C. and about 100° C.

15. The method according to claim 1 , further comprising cutting and polishing the monolithic heterogeneous product to form a smaller heterogeneous monolithic crystal.

16. The method according to claim 1 , further comprising forming a third crystal region on the Q-switch region, the third crystal region differing in composition from the Q-switch region.

17. The method according to claim 16 , wherein the third crystal region comprises undoped vanadate.

18. The method according to claim 16 , wherein the third crystal region is formed according to a method comprising heating and pressurizing an aqueous solution held within a second reactor to develop a temperature differential between a first zone of the second reactor and a second zone of the second reactor, the second reactor containing a vanadate forming feedstock in the first zone, this vanadate forming feedstock forming the same vanadate as the vanadate of the monolithic vanadate product crystal, the second reactor containing the vanadate product crystal in the second zone, wherein upon said heating and pressurizing growth of the third crystal region is initiated on the vanadate product crystal.

19. The method according to claim 1 , wherein the saturable absorber ion is included in the feedstock in a concentration between about 0.01 at. % and about 10 at. %.

20. The method according to claim 1 , the Q-switch region comprising an ion to balance the lattice charge of the Q-switch region.

Assignees

• Univ Clemson
• Clemson Univ Res Found

Inventors

• Kolis Joseph W
• Mcmillen Colin D
• Mann J Matthew

Classifications

• C30B7/00

  Single-crystal growth from solutions using solvents which are liquid at normal temperature, e.g. aqueous solutions (from molten solvents C30B9/00; by normal or gradient freezing C30B11/00; under a protective fluid C30B27/00) · CPC title

• C30B7/10 Primary

  by application of pressure, e.g. hydrothermal processes · CPC title

• C30B29/30

  Niobates; Vanadates; Tantalates · CPC title