Differential frequency generation
A fluid filled fiber for a quasi-phase matched generator and a laser incorporating such a fluid filled fiber. The laser has a liquid filled fiber with charge transfer molecules dissolved in a solvent. The liquid of the liquid filled fiber comprises or consists essentially of highly polar liquids and/or charge transfer molecules having relatively high molecular dipole values.
1 . A liquid filled quasi-phase matched optical parametric amplification fiber laser comprising:
a light source in optical communication with a light transmitting fiber having a cladding and a liquid filled core therein, the liquid being a polar liquid adapted for OPA wherein the liquid further comprises Zwitterionic molecules,
the fiber having a Λ/D value ranging from 2.3 to 666.7.
2 . A fiber laser according to claim 1 wherein the liquid further comprises imidazolium ionic liquids having dipole moments from 12 D to 14 D.
3 . A fiber laser according to claim 2 wherein the liquid is free of dopant.
4 . A fiber laser according to claim 1 wherein the liquid has a dielectric constant ranging from 1 to 40.
5 . A fiber laser according to claim 4 wherein the liquid comprises from 80 w/% to 95 w/% bromotrichloromethane and from 5 w % to 15 w/% perfluorohexane.
6 . A fiber laser according to claim 1 wherein wherein n core >n cladding .
7 . A fiber laser according to claim 1 wherein wherein n core <n cladding .
8 . A fiber laser according to claim 1 , wherein the liquid further comprises charge transfer molecules having a bond length alternation from −0.045 to +0.045 whereby the liquid is configured for OPA and OPG.
9 . A difference frequency generator comprising:
a light source in communication with a hollow core fiber,
the hollow fiber being filled with at least two mixed liquids not having mutually overlapping Raman lines, one said liquid with Λ from 100 μm to 1000 μm, and σ from 0.1 μm to 10 μm, and a gas with Λ from 1000 μm to 10000 μm, and σ 1 from 1.0 μm to 10 μm;
two spaced apart electrodes configured to enable second order wave mixing the liquid or gas inside the hollow fiber, and having an electrode period of 0.1-10.0% of Λ.
10 . A generator according to claim 9 satisfying the equation:
deff
,
QPM
DFG
=
k
*
χ
(
2
)
/
2.
11 . A generator according to claim 10 wherein Λ/D ranges from 3 to 500 and D is the separation distance between electrodes in microns.
12 . A method of making a liquid filled quasi-phase matched optical parametric amplification fiber laser comprising the steps of:
selecting a nonlinear liquid charge transfer molecule having a uB ranging from 2 to E-48 esu to 2 E-40 esu;
selecting a transmissive solvent;
combining the nonlinerar liquid charge transfer molecule and the NIR transmissive solvent to yield a liquid having a dielectric constant of 1.5 to 7.5 to thereby provide a QPM OPA/G gain/SRS gain ratio greater than 1; and
disposing the liquid in a light transmitting fiber in optical communication with a light source.
13 . A method according to claim 12 wherein the solvent is NIR transmissive.
14 . A method according to claim 13 wherein the solvent is transmissive to light having a wavelength of 0.8 to 10 microns.
15 . A method according to claim 14 wherein the solvent is transmissive to light having a wavelength of 1 to 2 microns.
16 . A method according to claim 15 wherein the solvent is selected from the group consisting of bromotrichloromethane, perfluorohexane, trichloroacetonitrile and combinations thereof.
17 . A method according to claim 15 wherein the solvent consists of at least 40% BTM.
18 . A method according to claim 14 wherein the liquid is free of zwitterionic dopant.