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Two-step phase-shifting SPIDER

View Article: PubMed Central - PubMed

ABSTRACT

Comprehensive characterization of ultrafast optical field is critical for ultrashort pulse generation and its application. This paper combines two-step phase-shifting (TSPS) into the spectral phase interferometry for direct electric-field reconstruction (SPIDER) to improve the reconstruction of ultrafast optical-fields. This novel SPIDER can remove experimentally the dc portion occurring in traditional SPIDER method by recording two spectral interferograms with π phase-shifting. As a result, the reconstructed results are much less disturbed by the time delay between the test pulse replicas and the temporal widths of the filter window, thus more reliable. What is more, this SPIDER can work efficiently even the time delay is so small or the measured bandwidth is so narrow that strong overlap happens between the dc and ac portions, which allows it to be able to characterize the test pulses with complicated temporal/spectral structures or narrow bandwidths.

No MeSH data available.


The /D(t) − D′(t)/ (black line) and /D(t)/ (blue line) when τ = 0.15 ps (a), the reconstructed temporal intensity and phase profiles (black lines) by TSPS-SPIDER (b). The temporal phases are also presented with red dashed line when τ = 0.4 ps and blue dashed line when τ = 0.5 ps for comparison.
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f2: The /D(t) − D′(t)/ (black line) and /D(t)/ (blue line) when τ = 0.15 ps (a), the reconstructed temporal intensity and phase profiles (black lines) by TSPS-SPIDER (b). The temporal phases are also presented with red dashed line when τ = 0.4 ps and blue dashed line when τ = 0.5 ps for comparison.

Mentions: As we know, if τ is small enough, as shown in Fig. 2(a) (τ = 0.15 ps), the dc and ac components of /D(t)/ will fail to separate entirely (blue line), so traditional SPIDER cannot work accurately, even correctly. Interestingly, the amplitude distribution of /D(t) − D′(t)/ shows the two ac components centered at t = ±τ are well separated at the absence of the dc, so it is still possible to carry out the electrical-field reconstruction of ultrashort light pulses. Figure 2(b) presents the corresponding temporal phase and intensity profiles using TSPS-SPIDER by the black lines: solid line for intensity and dashed line for phase. For convenience of comparison, the phase information of the optical field is also recovered with τ  = 0.4 ps (the red dashed line) and 0.5 ps (the blue dashed line) by TSPS-SPIDER, as shown in Fig. 2(b). One can see that the three temporal phases are coincident with each other, especially in the region from −100 to 100 fs, when the value of τ ranges from 0.15 ps to 0.5 ps. These results prove the TSPS-SPIDER is still available even τ is so small that the dc and the ac portions of /D(t)/ or /D′(t)/ overlap greatly with each other.


Two-step phase-shifting SPIDER
The /D(t) − D′(t)/ (black line) and /D(t)/ (blue line) when τ = 0.15 ps (a), the reconstructed temporal intensity and phase profiles (black lines) by TSPS-SPIDER (b). The temporal phases are also presented with red dashed line when τ = 0.4 ps and blue dashed line when τ = 0.5 ps for comparison.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC5036035&req=5

f2: The /D(t) − D′(t)/ (black line) and /D(t)/ (blue line) when τ = 0.15 ps (a), the reconstructed temporal intensity and phase profiles (black lines) by TSPS-SPIDER (b). The temporal phases are also presented with red dashed line when τ = 0.4 ps and blue dashed line when τ = 0.5 ps for comparison.
Mentions: As we know, if τ is small enough, as shown in Fig. 2(a) (τ = 0.15 ps), the dc and ac components of /D(t)/ will fail to separate entirely (blue line), so traditional SPIDER cannot work accurately, even correctly. Interestingly, the amplitude distribution of /D(t) − D′(t)/ shows the two ac components centered at t = ±τ are well separated at the absence of the dc, so it is still possible to carry out the electrical-field reconstruction of ultrashort light pulses. Figure 2(b) presents the corresponding temporal phase and intensity profiles using TSPS-SPIDER by the black lines: solid line for intensity and dashed line for phase. For convenience of comparison, the phase information of the optical field is also recovered with τ  = 0.4 ps (the red dashed line) and 0.5 ps (the blue dashed line) by TSPS-SPIDER, as shown in Fig. 2(b). One can see that the three temporal phases are coincident with each other, especially in the region from −100 to 100 fs, when the value of τ ranges from 0.15 ps to 0.5 ps. These results prove the TSPS-SPIDER is still available even τ is so small that the dc and the ac portions of /D(t)/ or /D′(t)/ overlap greatly with each other.

View Article: PubMed Central - PubMed

ABSTRACT

Comprehensive characterization of ultrafast optical field is critical for ultrashort pulse generation and its application. This paper combines two-step phase-shifting (TSPS) into the spectral phase interferometry for direct electric-field reconstruction (SPIDER) to improve the reconstruction of ultrafast optical-fields. This novel SPIDER can remove experimentally the dc portion occurring in traditional SPIDER method by recording two spectral interferograms with π phase-shifting. As a result, the reconstructed results are much less disturbed by the time delay between the test pulse replicas and the temporal widths of the filter window, thus more reliable. What is more, this SPIDER can work efficiently even the time delay is so small or the measured bandwidth is so narrow that strong overlap happens between the dc and ac portions, which allows it to be able to characterize the test pulses with complicated temporal/spectral structures or narrow bandwidths.

No MeSH data available.