Method and apparatus for ultra-violet-wavelength laser-induced fluorescence (UV-LIF) using optical output from a photonic-crystal rod
View Patent ↗A method and apparatus use a photonic-crystal fiber having a very large core while maintaining a single transverse mode. In some fiber lasers and amplifiers having large cores problems exist related to energy being generated at multiple-modes (i.e., polygamy), and of mode hopping (i.e., promiscuity) due to limited control of energy levels and fluctuations. The problems of multiple-modes and mode hopping result from the use of large-diameter waveguides, and are addressed by the invention. This is especially true in lasers using large amounts of energy (i.e., lasers in the one-megawatt or more range). By using multiple small waveguides in parallel, large amounts of energy can be passed through a laser, but with better control such that the aforementioned problems can be reduced. An additional advantage is that the polarization of the light can be maintained better than by using a single fiber core.
1. An apparatus comprising:
an optical transmitter component configured for use in a long-range optical measuring device, the component including:
a signal laser that emits a laser signal;
a first photonic-crystal optical device operatively coupled to receive the signal laser signal, the photonic-crystal optical amplifier device including a signal waveguide that has a diameter of at least 40 microns and maintains a single transverse mode, and
at least one wavelength-conversion optical medium operable to receive high-peak-power input radiation having a first wavelength from the signal waveguide of the first photonic-crystal device and to generate radiation having a peak power of at least about 100 kW and a second wavelength that is shorter than 400 nm through wavelength conversion.
2. The apparatus of claim 1 , wherein the wavelength-conversion optical medium includes at least one non-linear frequency doubler.
3. The apparatus of claim 1 , wherein the wavelength-conversion optical medium includes an optical parametric oscillator.
4. The apparatus of claim 1 , further comprising:
a detector configured to detect ultra-violet-wavelength laser-induced-fluorescence (UV-LIF), wherein the first photonic-crystal optical device is operated as part of an optical transmitter within a device that directs the optical beam towards an airborne cloud material to be analyzed; and
an analysis unit configured to detect specific substances.
5. The apparatus of claim 1 , wherein the analysis unit is configured to analyze inorganic chemicals.
6. The apparatus of claim 1 , wherein the analysis unit is configured to analyze organic chemicals.
7. The apparatus of claim 1 , wherein the analysis unit is configured to analyze biological compounds.
8. A method comprising:
obtaining a pulsed laser signal;
amplifying the signal laser signal using a photonic-crystal optical amplifier device that includes a signal waveguide that has a diameter of at least 40 microns and maintains a single transverse mode and generates, high-peak-power pulsed radiation; and
wavelength-converting the high-peak-power pulsed radiation having a first wavelength from the signal waveguide of the photonic-crystal device to generate radiation having a peak power of at least about 100 kW and a second wavelength that is shorter than 400 nm.
9. The method of claim 8 , wherein the wavelength-converting includes at least one non-linear frequency doubling.
10. The method of claim 8 , wherein the wavelength-converting includes optical parametric oscillating.
11. The method of claim 8 , further comprising:
optically transmitting the optical beam towards an airborne cloud material to be analyzed;
detecting ultra-violet-wavelength laser-induced-fluorescence (UV-LIF); and
analyzing the detected UV-LIF to detect specific substances.
12. The method of claim 8 , wherein the analyzing is configured to analyze inorganic chemicals.
13. The method of claim 8 , wherein the analyzing is configured to analyze organic chemicals.
14. The method of claim 8 , wherein the analyzing is configured to analyze biological compounds.
15. An apparatus comprising:
an optical transmitter component configured for use in a long-range optical measuring device, the component including:
a signal laser that emits a laser signal;
photonic-crystal means for amplifying the signal laser signal having a signal waveguide that has a diameter of at least 40 microns and maintains a single transverse mode and that generates high-peak-power pulsed radiation having a first wavelength; and
means for wavelength-converting the high-peak-power pulsed radiation to generate radiation having a peak power of at least about 100 kW and a second wavelength that is wavelength shorter than 400 nm.
16. The apparatus of claim 15 , wherein the means for wavelength-converting includes at least one non-linear means for frequency doubling.
17. The apparatus of claim 15 , wherein the means for wavelength-converting includes an optical parametric oscillator.
18. The apparatus of claim 15 , further comprising:
means for optically transmitting the optical beam towards an airborne cloud material to be analyzed;
means for detecting ultra-violet-wavelength laser-induced-fluorescence (UV-LIF); and
means for analyzing the detected UV-LIF to detect specific substances.
19. The apparatus of claim 15 , wherein the means for analyzing is configured to analyze inorganic chemicals.
20. The apparatus of claim 15 , wherein the means for analyzing is configured to analyze organic chemicals.
21. The apparatus of claim 15 , wherein the means for analyzing is configured to analyze biological compounds.