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Ultrafast and versatile spectroscopy by temporal Fourier transform.

Zhang C, Wei X, Marhic ME, Wong KK - Sci Rep (2014)

Bottom Line: One of the most remarkable and useful properties of a spatially converging lens system is its inherent ability to perform the Fourier transform; the same applies for the time-lens system.On the other hand, in addition to the single-lens structure, the multi-lens structures (e.g. telescope or wide-angle scope) will provide very versatile operating conditions.Leveraging the merit of instantaneous response, as well as the flexible lens structure, here we present a 100-MHz frame rate spectroscopy system - the parametric spectro-temporal analyzer (PASTA), which achieves 17 times zoom in/out ratio for different observation ranges.

View Article: PubMed Central - PubMed

Affiliation: Photonic Systems Research Laboratory, Department of Electrical and Electronic Engineering, The University of Hong Kong, Pokfulam Road, Hong Kong.

ABSTRACT
One of the most remarkable and useful properties of a spatially converging lens system is its inherent ability to perform the Fourier transform; the same applies for the time-lens system. At the back focal plane of the time-lens, the spectral information can be instantaneously obtained in the time axis. By implementing temporal Fourier transform for spectroscopy applications, this time-lens-based architecture can provide orders of magnitude improvement over the state-of-art spatial-dispersion-based spectroscopy in terms of the frame rate. On the other hand, in addition to the single-lens structure, the multi-lens structures (e.g. telescope or wide-angle scope) will provide very versatile operating conditions. Leveraging the merit of instantaneous response, as well as the flexible lens structure, here we present a 100-MHz frame rate spectroscopy system - the parametric spectro-temporal analyzer (PASTA), which achieves 17 times zoom in/out ratio for different observation ranges.

No MeSH data available.


Related in: MedlinePlus

Characterization of the cascaded SNR along the single-lens PASTA system.(a), Measured power budget, with the maximum and minimum input power of the dynamic range. (b), Estimated SNR variation along the channel. One more EDFA was added in front of the PASTA to further enhance the detection sensitivity, and the performance is shown by the dashed lines.
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f5: Characterization of the cascaded SNR along the single-lens PASTA system.(a), Measured power budget, with the maximum and minimum input power of the dynamic range. (b), Estimated SNR variation along the channel. One more EDFA was added in front of the PASTA to further enhance the detection sensitivity, and the performance is shown by the dashed lines.

Mentions: On the other hand, these PASTA prototypes have not been optimized for detection sensitivity and noise figure performance31. Figure 5 illustrates the basic structure of the single-lens PASTA system: two cascaded FWM-based wavelength conversion stages, as well as a booster amplifier in between. According to the aforementioned measurement, the signal sensitivity ranged from −32 dBm to 0 dBm, which were treated as the references for our analysis. The variations of the signal power between these boundaries are shown in Fig. 5(a). Here, we employed a 24-GHz PIN photodetector (Agilent, 83440D), with detection sensitivity down to −20 dBm. To further enhance the detection sensitivity, another booster amplifier was inserted in the front, as the dashed triangle shown in Fig. 5. It is noticed that there is a 20-dB improvement for the signal-to-noise ratio (SNR) at the output dispersion; since during the temporal converging process, the signal distributed across the 10-ns period was accumulated into the 50-ps pulsewidth. Therefore, the temporal intensity was enhanced by 20 dB. On the other hand, the distribution of the noise was unchanged such that the signal SNR was improved by 20 dB. With more accurate noise figure control, we believe that the PASTA system can achieve detection sensitivity as low as −50 dBm, which corresponds to 781 photons within the 10-ns time period.


Ultrafast and versatile spectroscopy by temporal Fourier transform.

Zhang C, Wei X, Marhic ME, Wong KK - Sci Rep (2014)

Characterization of the cascaded SNR along the single-lens PASTA system.(a), Measured power budget, with the maximum and minimum input power of the dynamic range. (b), Estimated SNR variation along the channel. One more EDFA was added in front of the PASTA to further enhance the detection sensitivity, and the performance is shown by the dashed lines.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4061551&req=5

f5: Characterization of the cascaded SNR along the single-lens PASTA system.(a), Measured power budget, with the maximum and minimum input power of the dynamic range. (b), Estimated SNR variation along the channel. One more EDFA was added in front of the PASTA to further enhance the detection sensitivity, and the performance is shown by the dashed lines.
Mentions: On the other hand, these PASTA prototypes have not been optimized for detection sensitivity and noise figure performance31. Figure 5 illustrates the basic structure of the single-lens PASTA system: two cascaded FWM-based wavelength conversion stages, as well as a booster amplifier in between. According to the aforementioned measurement, the signal sensitivity ranged from −32 dBm to 0 dBm, which were treated as the references for our analysis. The variations of the signal power between these boundaries are shown in Fig. 5(a). Here, we employed a 24-GHz PIN photodetector (Agilent, 83440D), with detection sensitivity down to −20 dBm. To further enhance the detection sensitivity, another booster amplifier was inserted in the front, as the dashed triangle shown in Fig. 5. It is noticed that there is a 20-dB improvement for the signal-to-noise ratio (SNR) at the output dispersion; since during the temporal converging process, the signal distributed across the 10-ns period was accumulated into the 50-ps pulsewidth. Therefore, the temporal intensity was enhanced by 20 dB. On the other hand, the distribution of the noise was unchanged such that the signal SNR was improved by 20 dB. With more accurate noise figure control, we believe that the PASTA system can achieve detection sensitivity as low as −50 dBm, which corresponds to 781 photons within the 10-ns time period.

Bottom Line: One of the most remarkable and useful properties of a spatially converging lens system is its inherent ability to perform the Fourier transform; the same applies for the time-lens system.On the other hand, in addition to the single-lens structure, the multi-lens structures (e.g. telescope or wide-angle scope) will provide very versatile operating conditions.Leveraging the merit of instantaneous response, as well as the flexible lens structure, here we present a 100-MHz frame rate spectroscopy system - the parametric spectro-temporal analyzer (PASTA), which achieves 17 times zoom in/out ratio for different observation ranges.

View Article: PubMed Central - PubMed

Affiliation: Photonic Systems Research Laboratory, Department of Electrical and Electronic Engineering, The University of Hong Kong, Pokfulam Road, Hong Kong.

ABSTRACT
One of the most remarkable and useful properties of a spatially converging lens system is its inherent ability to perform the Fourier transform; the same applies for the time-lens system. At the back focal plane of the time-lens, the spectral information can be instantaneously obtained in the time axis. By implementing temporal Fourier transform for spectroscopy applications, this time-lens-based architecture can provide orders of magnitude improvement over the state-of-art spatial-dispersion-based spectroscopy in terms of the frame rate. On the other hand, in addition to the single-lens structure, the multi-lens structures (e.g. telescope or wide-angle scope) will provide very versatile operating conditions. Leveraging the merit of instantaneous response, as well as the flexible lens structure, here we present a 100-MHz frame rate spectroscopy system - the parametric spectro-temporal analyzer (PASTA), which achieves 17 times zoom in/out ratio for different observation ranges.

No MeSH data available.


Related in: MedlinePlus