Tandem optical frequency mixer

Details Tandem optical frequency mixer Tandem optical frequency mixer

2000-01-12

2002-08-27

Lee, John D. (Department: 2874)

Optical: systems and elements

Optical frequency converter

C359S328000

Reexamination Certificate

active

06441948

ABSTRACT:

FIELD
The present invention relates to non-linear optical frequency conversion systems, and in particular to the design of optical frequency mixers.
BACKGROUND
Non-linear optical crystals have been used for optical frequency mixing.
FIG. 1
shows two laser frequencies &ohgr;
1
, &ohgr;
2
passing through a nonlinear optical (“NLO”) crystal
100
. The non-linear effect of the medium synthesizes a laser beam with a third frequency, &ohgr;
3
where &ohgr;
3
=&ohgr;
1
±&ohgr;
2
.
This nonlinear process is enhanced when the refractive index of the crystal is properly matched. This is called the phase matching condition. This proper match can be controlled by angle tuning of the crystal orientation with respect to the three laser beams &ohgr;
1
, &ohgr;
2
and &ohgr;
3
. Phase matching can also be carried out by changing the temperature, or by applying a difference electric field, etc.
An optical frequency mixer which has &ohgr;
1
=n*&ohgr;, &ohgr;
2
=m*&ohgr;, and &ohgr;
3
=(n+m)&ohgr;, where n,m are integers are greater than 0, is called a harmonic generator.
One example uses the fundamental of the Nd:YAG laser 1064 nm (&ohgr;
1
), the second harmonic at 532 nm (green, &ohgr;
532=&ohgr;
1064
+&ohgr;
1064
), and the fourth harmonic at 266 nm (Ultra-Violet, UV, &ohgr;
266
=&ohgr;
532+&ohgr;532
).
Optical frequency mixers allow a single laser source to be used for multiple different operations. For example, the fundamental output of a Nd:YAG laser is at 1064 nm. This frequency is not properly tuned to drill though many metals and plastics effectively. The fourth harmonic of 1064 nm, at 266 nm, however, allows the laser pulses to drill smooth holes with great ease in these materials.
Harmonics of lasers can also be used to pump tunable lasers, and enables covering a much broader spectral range. Optical frequency mixing research often attempts to generate higher power harmonics of solid state lasers such as Nd:YAG lasers in the deep UV range, e.g. <300 nm down to 190 nm. These deep UV sources are also used for microlithography. Deep UV sources permit small features e.g. 0.1 &mgr;m to be formed. Deep UV sources are also used for many industrial and scientific applications including inkjet nozzle drilling, laser eye surgery, trace gas monitoring and dissociation and others.
Although gas lasers could be used to generate a high power UV source, their size and the power consumed can be less favorable than current solid state lasers.


REFERENCES:
patent: 3619637 (1971-11-01), Goto
patent: 6215800 (2001-04-01), Komine

Affiliated with

Also associated with

Rating

Tandem optical frequency mixer does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Tandem optical frequency mixer, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Tandem optical frequency mixer will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2894223