Abstract: A chiral molecule can be defined as a molecule that has a non-superimposable mirror image. These mirror images can be referred to as enantiomers. The enantiomers generally have the same set of bond lengths and bond angles in their three-dimensional geometry. Apparatus and techniques described herein can be used to perform analysis of chiral molecules using cavity-enhanced molecular rotational spectroscopy. A sample cell can define a resonant cavity, and a sample introduction port can provide pulse-jet injection of an analyte molecule and a chiral tag to allow analysis of a complex comprising the analyte and chiral tag.

Abstract: A chiral molecule can be defined as a molecule that has a non-superimposable mirror image. These mirror images can be referred to as enantiomers. The enantiomers generally have the same set of bond lengths and bond angles in their three-dimensional geometry. Apparatus and techniques described herein can be used to perform analysis of chiral molecules using cavity-enhanced molecular rotational spectroscopy. A sample cell can define a resonant cavity, and a sample introduction port can provide pulse-jet injection of an analyte molecule and a chiral tag to allow analysis of a complex comprising the analyte and chiral tag.

Abstract: A chiral molecule can be defined as a molecule that has a non-superimposable mirror image. These mirror images can be referred to as enantiomers. The enantiomers generally have the same set of bond lengths and bond angles in their three-dimensional geometry. Apparatus and techniques described herein can be used to perform analysis of chiral molecules using cavity-enhanced molecular rotational spectroscopy. A sample cell can define a resonant cavity, and a sample introduction port can provide pulse jet injection of an analyte molecule and a chiral tag to allow analysis of a complex comprising the analyte and chiral tag.

Abstract: Methods and apparatuses for direct multiplication Fourier transform millimeter wave spectroscopy are disclosed herein. A sample method includes generating at least one pulse of microwave electromagnetic energy. The sample method also includes frequency-multiplying the pulse(s) to generate at least one frequency-multiplied pulse and filtering at least one spurious harmonic of the frequency-multiplied pulse to generate at least one filtered pulse. The spurious harmonic is generated by frequency-multiplying the pulse. The method also includes exciting a sample using the filtered pulse. The method further includes detecting an emission from the sample. The emission is elicited at least in part by the filtered pulse.

Abstract: Methods and apparatuses for direct multiplication Fourier transform millimeter wave spectroscopy are disclosed herein. A sample method includes generating at least one pulse of microwave electromagnetic energy. The sample method also includes frequency-multiplying the pulse(s) to generate at least one frequency-multiplied pulse and filtering at least one spurious harmonic of the frequency-multiplied pulse to generate at least one filtered pulse. The spurious harmonic is generated by frequency-multiplying the pulse. The method also includes exciting a sample using the filtered pulse. The method further includes detecting an emission from the sample. The emission is elicited at least in part by the filtered pulse.

Abstract: Methods and apparatuses for direct multiplication Fourier transform millimeter wave spectroscopy are disclosed herein. A sample method includes generating at least one pulse of microwave electromagnetic energy. The sample method also includes frequency-multiplying the pulse(s) to generate at least one frequency-multiplied pulse and filtering at least one spurious harmonic of the frequency-multiplied pulse to generate at least one filtered pulse. The spurious harmonic is generated by frequency-multiplying the pulse. The method also includes exciting a sample using the filtered pulse. The method further includes detecting an emission from the sample. The emission is elicited at least in part by the filtered pulse.

Abstract: A chiral molecule can be defined as a molecule that has a non-superimposable mirror image. These mirror images can be referred to as enantiomers. The enantiomers generally have the same set of bond lengths and bond angles in their three-dimensional geometry. Apparatus and techniques described herein can be used to perform analysis of chiral molecules using cavity-enhanced molecular rotational spectroscopy. A sample cell can define a resonant cavity, and a sample introduction port can provide pulse jet injection of an analyte molecule and a chiral tag to allow analysis of a complex comprising the analyte and chiral tag.

Abstract: An emission can be obtained from a sample in response to excitation using a specified range of excitation frequencies. Such excitation can include generating a specified chirped waveform and a specified downconversion local oscillator (LO) frequency using a digital-to-analog converter (DAC), upconverting the chirped waveform via mixing the chirped waveform with a specified upconversion LO frequency, frequency multiplying the upconverted chirped waveform to provide a chirped excitation signal for exciting the sample, receiving an emission from sample, the emission elicited at least in part by the chirped excitation signal, and downconverting the received emission via mixing the received emission with a signal based on the specified downconversion LO signal to provide a downconverted emission signal within the bandwidth of an analog-to-digital converter (ADC). The specified chirped waveform can include a first chirped waveform during a first duration, and a second chirped waveform during a second duration.

Abstract: Methods and apparatuses for direct multiplication Fourier transform millimeter wave spectroscopy are disclosed herein. A sample method includes generating at least one pulse of microwave electromagnetic energy. The sample method also includes frequency-multiplying the pulse(s) to generate at least one frequency-multiplied pulse and filtering at least one spurious harmonic of the frequency-multiplied pulse to generate at least one filtered pulse. The spurious harmonic is generated by frequency-multiplying the pulse. The method also includes exciting a sample using the filtered pulse. The method further includes detecting an emission from the sample. The emission is elicited at least in part by the filtered pulse.

Abstract: Apparatus and techniques for broadband Fourier transform spectroscopy can include frequency hopping spread-spectrum spectroscopy approaches. For example, an excitation source power can be spread over a specified frequency bandwidth, such as by applying a sequence of short, transform-limited pulses to a sample. Each pulse can include a specified carrier frequency, and a corresponding bandwidth of the individual pulse can be determined by a frequency domain representation when Fourier transformed. A series of short excitation pulses can be used to create an excitation sequence, such as to deliver a specified or desired amount of power to the sample, such as by having the excitation source enabled for a time comparable to a free induction decay (FID) dephasing time.

Abstract: Examples herein include apparatus and techniques that can be used to perform rotational spectroscopy on gas-phase samples. Such techniques can include using a spectrometer providing frequency synthesis and pulse modulation to provide excitation (e.g., pump or probe pulses) of a gas-phase sample at mm-wave frequencies. Synthesis of such mm-wave frequencies can include use of a frequency multiplier, such as an active multiplier chain (AMC). A free induction decay (FID) elicited by the excitation or other time-domain information can be obtained from the sample, such as down-converted and digitized. A frequency domain representation of the digitized information, such as a Fourier transformed representation, can be used to provide a rotational spectrum.

Abstract: An emission can be obtained from a sample in response to excitation using a specified range of excitation frequencies. Such excitation can include generating a specified chirped waveform and a specified downconversion local oscillator (LO) frequency using a digital-to-analog converter (DAC), upconverting the chirped waveform via mixing the chirped waveform with a specified upconversion LO frequency, frequency multiplying the upconverted chirped waveform to provide a chirped excitation signal for exciting the sample, receiving an emission from sample, the emission elicited at least in part by the chirped excitation signal, and downconverting the received emission via mixing the received emission with a signal based on the specified downconversion LO signal to provide a downconverted emission signal within the bandwidth of an analog-to-digital converter (ADC). The specified chirped waveform can include a first chirped waveform during a first duration, and a second chirped waveform during a second duration.

Abstract: A pulse train comprising chirped pulses can be used to excite a sample, such as for spectroscopic analysis. The respective chirped pulses can include a frequency sweep to establish a first frequency-domain comb. A width of frequency-domain comb peaks can be established at least in part by a total duration of the pulse train, and a bandwidth of the first frequency-domain comb can be determined at least in part by a bandwidth of the frequency sweep of the respective chirped pulses. A free-space or enclosed sample interaction region can be used.

Abstract: An emission can be obtained from a sample in response to excitation using a specified range of excitation frequencies. Such excitation can include generating a specified chirped waveform and a specified downconversion local oscillator (LO) frequency using a digital-to-analog converter (DAC), upconverting the chirped waveform via mixing the chirped waveform with a specified upconversion LO frequency, frequency multiplying the upconverted chirped waveform to provide a chirped excitation signal for exciting the sample, receiving an emission from sample, the emission elicited at least in part by the chirped excitation signal, and downconverting the received emission via mixing the received emission with a signal based on the specified downconversion LO signal to provide a downconverted emission signal within the bandwidth of an analog-to-digital converter (ADC). The specified chirped waveform can include a first chirped waveform during a first duration, and a second chirped waveform during a second duration.

Abstract: An emission can be obtained from a sample in response to excitation using a specified range of excitation frequencies. Such excitation can include generating a specified chirped waveform and a specified downconversion local oscillator (LO) frequency using a digital-to-analog converter (DAC), upconverting the chirped waveform via mixing the chirped waveform with a specified upconversion LO frequency, frequency multiplying the upconverted chirped waveform to provide a chirped excitation signal for exciting the sample, receiving an emission from sample, the emission elicited at least in part by the chirped excitation signal, and downconverting the received emission via mixing the received emission with a signal based on the specified downconversion LO signal to provide a downconverted emission signal within the bandwidth of an analog-to-digital converter (ADC). The specified chirped waveform can include a first chirped waveform during a first duration, and a second chirped waveform during a second duration.

Abstract: Apparatus and techniques for broadband Fourier transform spectroscopy can include frequency hopping spread-spectrum spectroscopy approaches. For example, an excitation source power can be spread over a specified frequency bandwidth, such as by applying a sequence of short, transform-limited pulses to a sample. Each pulse can include a specified carrier frequency, and a corresponding bandwidth of the individual pulse can be determined by a frequency domain representation when Fourier transformed. A series of short excitation pulses can be used to create an excitation sequence, such as to deliver a specified or desired amount of power to the sample, such as by having the excitation source enabled for a time comparable to a free induction decay (FID) dephasing time.

Abstract: A pulse train comprising chirped pulses can be used to excite a sample, such as for spectroscopic analysis. The respective chirped pulses can include a frequency sweep to establish a first frequency-domain comb. A width of frequency-domain comb peaks can be established at least in part by a total duration of the pulse train, and a bandwidth of the first frequency-domain comb can be determined at least in part by a bandwidth of the frequency sweep of the respective chirped pulses. A free-space or enclosed sample interaction region can be used.

Abstract: An emission can be obtained from a sample in response to excitation using a specified range of excitation frequencies. Such excitation can include generating a specified chirped waveform and a specified downconversion local oscillator (LO) frequency using a digital-to-analog converter (DAC), upconverting the chirped waveform via mixing the chirped waveform with a specified upconversion LO frequency, frequency multiplying the upconverted chirped waveform to provide a chirped excitation signal for exciting the sample, receiving an emission from sample, the emission elicited at least in part by the chirped excitation signal, and downconverting the received emission via mixing the received emission with a signal based on the specified downconversion LO signal to provide a downconverted emission signal within the bandwidth of an analog-to-digital converter (ADC). The specified chirped waveform can include a first chirped waveform during a first duration, and a second chirped waveform during a second duration.

Abstract: A pulse train comprising chirped pulses can be used to excite a sample, such as for spectroscopic analysis. The respective chirped pulses can include a frequency sweep to establish a first frequency-domain comb. A width of frequency-domain comb peaks can be established at least in part by a total duration of the pulse train, and a bandwidth of the first frequency-domain comb can be determined at least in part by a bandwidth of the frequency sweep of the respective chirped pulses. A free-space or enclosed sample interaction region can be used.

Abstract: Examples herein include apparatus and techniques that can be used to perform rotational spectroscopy on gas-phase samples. Such techniques can include using a spectrometer providing frequency synthesis and pulse modulation to provide excitation (e.g., pump or probe pulses) of a gas-phase sample at mm-wave frequencies. Synthesis of such mm-wave frequencies can include use of a frequency multiplier, such as an active multiplier chain (AMC). A free induction decay (FID) elicited by the excitation or other time-domain information can be obtained from the sample, such as down-converted and digitized. A frequency domain representation of the digitized information, such as a Fourier transformed representation, can be used to provide a rotational spectrum.