Coherent light generators – Particular beam control device – Mode discrimination
Patent
1996-12-19
1999-06-29
Scott, Jr., Leon
Coherent light generators
Particular beam control device
Mode discrimination
372 16, 372 31, 372 25, 372 97, 372 23, 372100, 372 22, 372 92, 372 10, H01S 3098
Patent
active
059178434
DESCRIPTION:
BRIEF SUMMARY
FIELD OF THE INVENTION
This invention relates to a laser cavity assembly adapted to emit at more than one wavelength. In other aspects, the invention is concerned with a novel Q-switch device and with a combination laser oscillator and dual mode means.
BACKGROUND ART
Nd:YAG lasers operating at 1.06 .mu.m wavelength are very well known. These lasers have been deployed in a wide range of applications.
More recently, there has been considerable interest in lasers operating with output around 1.5 .mu.m wavelength, because the eye is far less susceptible to damage at this wavelength. These lasers are often referred to as eyesafe lasers, and generally they are either based on Erbium doped glass or YAG (operating fundamentally at around 1.5 .mu.m), or rely on parametric or other conversion from a different fundamental wavelength. For example, eyesafe lasers based upon Nd:YAG lasers and conversion from 1.06 to 1.5 .mu.m by Raman or OPO (optical parametric oscillator) are known.
Many sensors in military and other applications operate only at 1.06 .mu.m, and replacement of the laser source is inhibited by the prohibitive cost of replacing all sensors. For example, laser guided weapons exist in large stockpiles with systems configured for 1.06 .mu.m. However, the operational platforms which designate targets for these weapons require eyesafe lasers for new applications. Often there are space, eight, and maintenance considerations mitigating against proliferation of laser sources on forward-deployed platforms. Nevertheless, systems are now being provided with separate lasers for different parts of the system, for example 1.06 .mu.m lasers for the laser designator components, and 1.51 .mu.m lasers for the range finders.
DISCLOSURE OF THE INVENTION
It is therefore an object of the invention, in at least a first aspect, to provide a single configuration which is adaptable to selectably generate radiation at two or more different wavelengths.
To meet this object, the invention provides, in a first aspect, a laser cavity assembly comprising:
means defining respective optical resonance cavities for stimulated radiation of different wavelengths, which cavities include at least some common volume, such means including window means for emission of radiation amplified in the respective cavities,
means in one of said cavities responsive to stimulated radiation emitted by a laser medium at one of said wavelengths to emit radiation at another of said wavelengths; and
dual mode means having respective selectable first and second modes at which the laser cavity assembly is adapted to emit laser radiation predominantly at the respective wavelengths.
In one embodiment, the responsive means is responsive to stimulated radiation emitted by a laser medium at one of said wavelengths having one or more prescribed characteristics to emit radiation at another of said wavelengths, and wherein in the respective first and second modes of said dual mode means, radiation of said one wavelength respectively possesses and does not possess said prescribed characteristic. The prescribed characteristic may advantageously be a particular range of intensity of stimulated radiation.
The means defining the respective cavities may include the dual mode means, which may define an end mirror for each cavity. In the latter case, the dual mode means may comprise a device configured whereby, in one of said modes, the dual mode means comprises Q-switch means. For example, the end mirror may be a rotatable Porro prism having respective selectable modes. The prism may be rotatable as a conventional Q-switch in said first mode, whereby the prescribed characteristic of said radiation is short pulse/high intensity. In the second mode, the prism is configured to be retro-reflective and thereby to generate long pulse/low intensity radiation at said one wavelength.
In another embodiment, the dual mode means comprises an optical switch including a fully reflecting portion and a partially reflecting portion, which switch is selectively operable to alternate said po
REFERENCES:
patent: 3860888 (1975-01-01), Stephens
patent: 4408334 (1983-10-01), Lundstrom
patent: 4420836 (1983-12-01), Harper
patent: 4525034 (1985-06-01), Simmons
patent: 4564949 (1986-01-01), Trolinger
patent: 4660204 (1987-04-01), Dewhirst
patent: 4675500 (1987-06-01), Kunz et al.
patent: 4677639 (1987-06-01), Sasser
patent: 4740986 (1988-04-01), Reeder
patent: 4751720 (1988-06-01), Koop
patent: 4809282 (1989-02-01), Dewhrist
Bethea; "Megawatt Power at 1.318.mu. in Nd:YAG and Simultaneous Oscillation at Both 1.06 and 1.318.mu."; IEEE Jour. Quantum Elect.;Feb,1993.
Electro Optic Systems Pty.
Jr. Leon Scott
LandOfFree
Laser cavity assembly does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Laser cavity assembly, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Laser cavity assembly will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1382878