초록 ▼

Methods and systems for wavelength locking free OFC based DIAL are disclosed, including generating electromagnetic radiation from a mode-locked fiber laser; coupling the electromagnetic radiation to an acousto-optic modulator; coupling the electromagnetic radiation to a power amplifier; collimating

Methods and systems for wavelength locking free OFC based DIAL are disclosed, including generating electromagnetic radiation from a mode-locked fiber laser; coupling the electromagnetic radiation to an acousto-optic modulator; coupling the electromagnetic radiation to a power amplifier; collimating and coupling the amplified electromagnetic radiation into a scanner; steering the collimated and amplified electromagnetic radiation onto a target; using a telescope to collect a portion of the backscattered electromagnetic radiation from the target; coupling the collected portion of the backscattered electromagnetic radiation into a DWDM; using a photon counting receiver coupled to the DWDM to measure a multiple OFC on-resonant band intensity and a multiple OFC off-resonant band intensity; and comparing the multiple OFC on-resonant band intensity with the multiple OFC off-resonant band intensity in order to determine one or more concentrations of one or more molecules within the target. Other embodiments are described and claimed.

대표청구항 ▼

1. A differential absorption Lidar comprising: a mode-locked fiber laser, wherein the mode-locked fiber laser generates an electromagnetic radiation, wherein the electromagnetic radiation comprises an optical frequency comb with a frequency comb spacing of a pulsed repetition rate of the mode-locked

1. A differential absorption Lidar comprising: a mode-locked fiber laser, wherein the mode-locked fiber laser generates an electromagnetic radiation, wherein the electromagnetic radiation comprises an optical frequency comb with a frequency comb spacing of a pulsed repetition rate of the mode-locked fiber laser;an acousto-optic modulator comprising an input and an output, wherein the electromagnetic radiation is coupled to the input of the acousto-optic modulator and wherein the acousto-optic modulator is configured to down select the pulse repetition rate of the electromagnetic radiation;a power amplifier comprising an input and an output, wherein the input of the power amplifier is coupled to the output of the acousto-optic modulator and wherein the power amplifier is configured to amplify the down selected pulse repetition rate electromagnetic radiation;a collimator comprising an input and an output, wherein the input of the collimator is coupled to the output of the power amplifier and wherein the collimator is configured to collimate the amplified down selected pulse repetition rate electromagnetic radiation;an azimuth and elevation scanner comprising an input and an output, wherein the input of the azimuth and elevation scanner is coupled to the output of the collimator and wherein the azimuth and elevation scanner is configured to steer the collimated amplified down selected pulse repetition rate electromagnetic radiation onto a target;a telescope comprising an input and an output, wherein the input of the telescope is configured to collect electromagnetic radiation backscattered from the target;a DWDM comprising an input and an output, wherein the input of the DWDM is coupled to the output of the telescope;a photon counting receiver, wherein the photon counting receiver is coupled to the output of the DWDM;a signal processing and control unit, wherein the signal processing and control unit is coupled to the photon counting receiver and wherein the signal processing and control unit is configured to synchronize and gate the mode-locked fiber laser, the acousto-optic modulator, and the photon counting receiver; anda computer coupled to the signal processing and control unit, wherein the computer is configured to compare an on-resonant band intensity of the backscattered electromagnetic radiation with an off-resonant band intensity of the backscattered electromagnetic radiation. 2. The differential absorption Lidar of claim 1, wherein the pulse repetition rate of the electromagnetic radiation generated from the mode-locked fiber laser ranges from about 1 to 100 MHz. 3. The differential absorption Lidar of claim 1, wherein the pulse repetition rate of the down selected electromagnetic radiation ranges from about 1 to 100 kHz. 4. The differential absorption Lidar of claim 1, wherein the amplified down selected pulse repetition rate electromagnetic radiation comprises: a power greater than about 1 W;an energy greater than about 1 μJ; anda pulse width from 0.1 ps to 200 ns. 5. The differential absorption Lidar of claim 1, wherein the azimuth and elevation scanner comprises dual oscillating plane mirrors. 6. The differential absorption Lidar of claim 1, wherein the photon counting receiver comprises a single photon avalanche photodiode or a photomultiplier tube. 7. The differential absorption Lidar of claim 1, wherein the power amplifier comprises a doped fiber amplifier. 8. The differential absorption Lidar of claim 7, wherein the doped fiber amplifier comprises a doped gain medium comprising at least one of: Er, Yb, Tm, Ho, Er/Yb, Er:ZBLAN, Ho:ZBLAN, and Tm:ZBLAN. 9. The differential absorption Lidar of claim 7, wherein the doped fiber amplifier comprises a fiber material comprising at least one of: silica, Germanium, Fluoride, Chalcogenide, and ZBLAN. 10. The differential absorption Lidar of claim 1, further comprising an OPO and/or an OPA, wherein the OPO and/or the OPA are configured to extend spectral wavelength ranges of the electromagnetic radiation. 11. The differential absorption Lidar of claim 1, wherein the amplified down selected pulse repetition rate electromagnetic radiation spans from NIR to MWIR and/or LWIR. 12. A method for differential absorption Lidar comprising: generating electromagnetic radiation from a mode-locked fiber laser, wherein the electromagnetic radiation comprises an optical frequency comb with a frequency comb spacing of a pulsed repetition rate of the mode-locked fiber laser;coupling the electromagnetic radiation from the mode-locked fiber laser to an acousto-optic modulator, wherein the acousto-optic modulator is configured to down select the pulse repetition rate of the electromagnetic radiation;coupling the down selected pulse repetition rate electromagnetic radiation to a power amplifier, wherein the power amplifier is configured to amplify the down selected pulse repetition rate electromagnetic radiation;collimating and coupling the amplified down selected pulse repetition rate electromagnetic radiation into an azimuth and elevation scanner, wherein the azimuth and elevation scanner is configured to steer the collimated amplified down selected pulse repetition rate electromagnetic radiation;steering the collimated and amplified down selected pulse repetition rate electromagnetic radiation onto a target, wherein the target backscatters a portion of the collimated and amplified down selected pulse repetition rate electromagnetic radiation;using a telescope to collect a portion of the backscattered electromagnetic radiation;coupling the collected portion of the backscattered electromagnetic radiation into a DWDM;using a photon counting receiver coupled to the DWDM to measure a multiple OFC on-resonant band intensity and a multiple OFC off-resonant band intensity; andcomparing the multiple OFC on-resonant band intensity with the multiple OFC off-resonant band intensity in order to determine one or more concentrations of one or more molecules within the target. 13. The method of claim 12 further comprising combining multiple channels of electromagnetic radiation in order to determine the one or more concentrations of the one or more molecules within the target as a function of distance. 14. The method of claim 12, wherein the pulse repetition rate of the electromagnetic radiation generated from the mode-locked fiber laser ranges from about 1 to 100 MHz. 15. The method of claim 12, wherein the pulse repetition rate of the down selected electromagnetic radiation ranges from about 1 to 100 kHz. 16. The method of claim 12, wherein the amplified down selected pulse repetition rate electromagnetic radiation comprises: a power greater than about 1 W;an energy greater than about 1 μJ; anda pulse width from 0.1 ps to 200 ns. 17. The method of claim 12, wherein the azimuth and elevation scanner comprises dual oscillating plane mirrors. 18. The method of claim 12, wherein the photon counting receiver comprises a single photon avalanche photodiode or a photomultiplier tube. 19. The method of claim 12, wherein the power amplifier comprises a doped fiber amplifier. 20. The method of claim 19, wherein the doped fiber amplifier comprises a doped gain medium comprising at least one of: Er, Yb, Tm, Ho, Er/Yb, Er:ZBLAN, Ho:ZBLAN, and Tm:ZBLAN. 21. The method of claim 19, wherein the doped fiber amplifier comprises a fiber material comprising at least one of: silica, Germanium, Fluoride, Chalcogenide, and ZBLAN. 22. The method of claim 12 further comprising using an OPO and/or an OPA to extend spectral wavelength ranges of the electromagnetic radiation. 23. The method of claim 12, wherein the amplified down selected pulse repetition rate electromagnetic radiation spans from NIR to MWIR and/or LWIR.