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(a) Temporal shape after the pulses propagate through 9.5 mm of fused silica, showing the intensity (solid curve) and the phase (dashed curve). The FWHM of the pulse intensity is 89 fs. (c) Temporal shape after pulse compression by the calibrated method. The FWHM is 15.2 fs, and the transform limit is 14.5 fs. ( b), (d ) Solid curves, corresponding spectra and dashed curves, group delay for cases (a) and (c), respectively.
Source publication
A micromachined deformable mirror (MMDM) is used as phase modulator for laser pulse compression. The silicon nitride membrane MMDM uses electrostatic force to deform the reflecting surfaces. Genetic algorithm search and mirror calibration are used to test the operation of the MMDM in multiple steps and in single step, respectively. The output pulse...
Citations
... There are many designs of pulse shapers, including ones that utilize acousto-optic programable dispersive filters (AOPDF), spatial light modulator (SLM), micromirrors, and deformable mirrors [4,7,[20][21][22]. One common design is the transverse pulse shaper that operates on the pulse in the frequency domain and consists of two gratings, focusing optics, and a programmable filter in a 4-f optical layout as shown in Fig. 1(a). ...
We present a frequency domain, AOM-based pulse shaper that utilizes Brewster prisms rather than the current standard of gratings. In doing so, we demonstrate a three-fold increase in efficiency and the ability to compensate for temporal dispersion created by the acousto-optic modulator that filters the pulse spectrum. The shaper is tested between the wavelengths of 520-660 and 840-1170 nm, creating sub-50 fs pulses for each, and used to collect a 2D white-light spectrum of a thin film of semiconducting carbon nanotubes.
... The compression of such pulses to achieve pulse durations <10 fs is a challenging task. Advanced dispersion control in the spectral domain via pulse shaping [38,60,61] or deformable mirrors [62,63] have limited performance in the blue part of the spectrum. Also, the blue spectral components may lead to photo damage in liquid-crystal-based spatial light modulators. ...
Two-dimensional electronic spectroscopy (2DES) is a powerful method to study coherent and incoherent interactions and dynamics in complex quantum systems by correlating excitation and detection energies in a nonlinear spectroscopy experiment. Such dynamics can be probed with a time resolution limited only by the duration of the employed laser pulses and in a spectral range defined by the pulse spectrum. In the blue spectral range (<500 nm), the generation of sufficiently broadband ultrashort pulses with pulse durations of 10 fs or less has been challenging so far. Here, we present a 2DES setup based on a hollow-core fiber supercontinuum covering the full visible range (400-700 nm). Pulse compression via custom-made chirped mirrors yields a time resolution of <10 fs. The broad spectral coverage, in particular the extension of the pulse spectra into the blue spectral range, unlocks new possibilities for coherent investigations of blue-light absorbing and multichromophoric compounds, as demonstrated by a 2DES measurement of chlorophyll a.
... Finally, it is important to note that a variety of techniques can be used in experiments to shape pulses and process desired optical waveforms 51,52 . For example, the spatial light modulating programs 53 , micro-lithographic pattern technique 54 , the deformable mirrors 55 , and the acoustic-optic modulators 56 are a few of them. ...
The preservation of quantum correlations requires optimal procedures and the proper design of the transmitting channels. In this regard, we address designing a hybrid channel comprising a single-mode cavity accompanied by a super-Gaussian beam and local dephasing parts based on the dynamics of quantum characteristics. We choose two-level atoms and various functions such as traced-distance discord, concurrence, and local-quantum uncertainty to analyze the effectiveness of the hybrid channel to preserve quantum correlations along with entropy suppression discussed using linear entropy. The joint configuration of the considered fields is found to not only preserve but also generate quantum correlations even in the presence of local dephasing. Most importantly, within certain limits, the proposed channel can be readily regulated to generate maximal quantum correlations and complete suppression of the disorder. Besides, compared to the individual parts, mixing the Fock state cavity, super-Gaussian beam, and local dephasing remains a resourceful choice for the prolonged quantum correlations’ preservation. Finally, we present an interrelationship between the considered two-qubit correlations’ functions, showing the deviation between each two correlations and of the considered state from maximal entanglement under the influence of the assumed hybrid channel.
... Depending on the laser platform, pulse-shaping limitations that might arise in the amplifier chain when using a pulse shaper in the laser front-end can be circumvented by direct phase shaping of the amplified laser pulses. A high-power phase shaper can be implemented, for example, via a phase mask or deformable mirror in the CPA compressor 33 . ...
The serrodyne principle enables an electromagnetic signal to be frequency shifted by applying a linear phase ramp in the time domain. This phenomenon has been exploited to frequency shift signals in the radiofrequency, microwave and optical regions of the electromagnetic spectrum over ranges of up to a few gigahertz, for example, to analyse the Doppler shift of radiofrequency signals for noise suppression and frequency stabilization. Here we employ this principle to shift the centre frequency of high-power femtosecond laser pulses over a range of several terahertz with the help of a nonlinear multi-pass cell. We demonstrate our method experimentally by shifting the central wavelength of a state-of-the-art 75 W frequency comb laser from 1,030 nm to 1,060 nm and to 1,000 nm. Furthermore, we experimentally show that this wavelength-shifting technique supports coherence characteristics at the few hertz-level while improving the temporal pulse quality. The technique is generally applicable to wide parameter ranges and different laser systems, enabling efficient wavelength conversion of high-power lasers to spectral regions beyond the gain bandwidth of available laser platforms.
... In order to control the FOD, several dispersion compensation methods have been developed. For example, mechanically deformable mirror [16], liquid-crystal modulator [17], grism pair [18], acousto-optic programmable dispersive filter (AOPDF) [19], and negative and positive chirped pulse amplification (NPCPA) scheme [20]. Limited by the dynamic range and spectral resolution, deformable mirror and liquid-crystal modulator are seldom applied in high peak power lasers. ...
We report dispersion management based on a mismatched-grating compressor for a 100 PW level laser, which utilizes optical parametric chirped pulse amplification and also features large chirped pulse duration and an ultra-broadband spectrum. The numerical calculation indicates that amplified pulses with 4 ns chirped pulse duration and 210 nm spectral bandwidth can be directly compressed to sub-13 fs, which is close to the Fourier-transform limit (FTL). More importantly, the tolerances of the mismatched-grating compressor to the misalignment of the stretcher, the error of the desired grating groove density and the variation of material dispersion are comprehensively analyzed, which is crucially important for its practical application. The results demonstrate that good tolerances and near-FTL compressed pulses can be achieved simultaneously, just by keeping a balance between the residual second-, third- and fourth-order dispersions in the laser system. This work can offer a meaningful guideline for the design and construction of 100 PW level lasers.
... However, the ETL performance is readily affected by gravity and temperature. Accordingly, deformable mirrors (DMs), which also have a millisecond response, have found increasing use for pulse compression applications in recent decades [32,33]. DMs modulate the spectral phase through the application of a high voltage to an array of actuators, which then deform the reflective membrane as required [34]. ...
The optical dispersion effect in ultrafast pulse laser systems broadens the laser pulse duration and reduces the theoretical peak power. The present study proposes an adaptive ultrashort pulse compressor for compensating the optical dispersion using a direct optical-dispersion estimation by spectrogram (DOES) method. The DOES has fast and accurate computation time which is suitable for real time controller design. In the proposed approach, the group delay dispersion (GDD) and its polarity are estimated directly from the delay marginal of the trace obtained from a single-shot frequency-resolved optical gating (FROG). The estimated GDD is then processed by a closed-loop controller, which generates a command signal to drive a linear deformable mirror as required to achieve the desired laser pulse compression. The dispersion analysis, control computation, and deformable mirror control processes are implemented on a single field programmable gate array (FPGA). It is shown that the DOES dispersion computation process requires just 0.5 ms to complete. Moreover, the proposed pulse compressor compensates for both static dispersion and dynamic dispersion within five time steps when closed-loop controller is performed at a frequency of 100 Hz. The experimental results show that the proposed pulse compressor yields an effective fluorescence intensity improvement in a multiphoton excited fluorescence microscope (MPEFM).
... 1,3,4 Different kinds of masks can be employed for pulse shaping, such as liquid crystal modulators, 5,6 acousto-optic modulators, 7,8 micro-mechanical deformable mirror, 9 and microelectro-mechanical systems. 10 This pulse shaping approach and the temporal profile tailoring allowed coherent quantum control of matter 11,12 and chemical reactions. [13][14][15] Another pulse shaping and waveform synthesis technique can be realized by controlling the amplitude and the frequency comb's harmonics phase. ...
The advancement of the ultrafast pulse shaping and waveform synthesis allowed to coherently control the atomic and electronic motions in matter. The temporal resolution of the waveform synthesis is inversely proportional to the broadening of its spectrum. Here, we demonstrate the light field synthesis of high-power waveforms spanning two optical octaves, from near-infrared (NIR) to deep-ultraviolet (DUV) with attosecond resolution. Moreover, we utilized the all-optical field sampling metrology for on-demand tailoring of light field waveforms to control the electron motion in matter. The demonstrated synthesis of the light field and the electron motion control pave the way for switching the photo-induced current signal in dielectric nanocircuit and establishing ultrafast photonics operating beyond the petahertz speed.
... The ray tracing results are presented in Fig. 5. Using the measured UV spectrum, we obtain a theoretical pulse duration of 8.8 fs, which is in good agreement with the experimental data. This result implies that DUV pulses of ≈ 10 fs duration can be achieved solely with standard optics, without the need of advanced compression techniques based on deformable mirrors, liquid-crystal displays or acousto-optic elements [42][43][44]. ...
The generation and characterization of ultrashort laser pulses in the deep ultraviolet spectral region is challenging, especially at high pulse repetition rates and low pulse energies. Here, we combine achromatic second harmonic generation and adaptive pulse compression for the efficient generation of sub-10 fs deep ultraviolet laser pulses at a laser repetition rate of 200 kHz. Furthermore, we simplify the pulse compression scheme and reach pulse durations of ≈10 fs without the use of adaptive optics. We demonstrate straight-forward tuning from 250 to 320 nm, broad pulse spectra of up to 63 nm width, excellent stability and a high robustness against misalignment. These features make the approach appealing for numerous spectroscopy and imaging applications.
... 2D spectra and conversion to Einstein B 2D spectra A femtosecond Ti:sapphire regenerative amplifier operating at 1-kHz repetition rate pumps a noncollinear optical parametric amplifier (58) to generate the femtosecond short-wave infrared pulses used for 2D spectroscopy. The pulses are compressed down to ~16 fs by a deformable mirror grating compressor using an adaptive algorithm (58,59). The pulses used for this experiment have energies of 3.6 J with a stability better than 0.4%. ...
For quantum-confined nanomaterials, size dispersion causes a static broadening of spectra that has been difficult to measure and invalidates all-optical methods for determining the maximum photovoltage that an excited state can generate. Using femtosecond two-dimensional (2D) spectroscopy to separate size dispersion broadening of absorption and emission spectra allows a test of single-molecule generalized Einstein relations between such spectra for colloidal PbS quantum dots. We show that 2D spectra and these relations determine the thermodynamic standard chemical potential difference between the lowest excited and ground electronic states, which gives the maximum photovoltage. Further, we find that the static line broadening from many slightly different quantum dot structures allows single-molecule generalized Einstein relations to determine the average single-molecule linewidth from Stokes’ frequency shift between ensemble absorption and emission spectra.
... Due to the high adaptability of morphing, some researchers developed morphing components in engineering products (e.g., in the field of aerospace engineering) [32][33][34][35]. However, while the surface morphing technology has not yet appeared in real mechanical products, some morphing surfaces are used in the optics, biology, and medical industries [36][37][38]. ...
As the need for higher efficiency of engineering components increases, so does the demand for functional surfaces. While various tribosurfaces (e.g., texturing and coatings) have been developed, many researches are aimed at static functionality. On the other hand, due to a wide range of environmental adaptability and active control, active-morphing surfaces can be highly efficient and robust. In this paper, we demonstrate a novel morphing surface and its realization using additive manufacturing (AM). By using a diaphragm structure, morphing performance is achieved even if a hard resin material is used. When air pressure is applied to the backside of the diaphragm, it changes to a convex shape, and vice versa. The concept requires a complex structure for arranging airflow and a solid morphing system. The AM is one great technique to create such complex structure. As a result of actual manufacturing, the created morphing structure realizes a large morphing of 600 µm or more. In addition, the shape changes reversibly depending on the air pressure. The surface also exhibits very interesting tribological characteristics. The surface shows a friction coefficient of 0.5-1.7 with a convexity, and then decreases to about 0.3 with a concavity. A real-contact area measurement reveals that the novel property occurs due to change in the real-contact area depending on surface morphology. In conclusion, the present paper provides a new concept of a novel morphing tribosurface, which selectively performs as a low-friction or break-like surface, created using AM.
