Measurement Of Ultrashort Optical Pulses Research Articles

Fourier fringe analysis and its application to metrology of extreme physical phenomena: a review [Invited

The paper reviews a technique for fringe analysis referred to as Fourier fringe analysis (FFA) or the Fourier transform method, with a particular focus on its application to metrology of extreme physical phenomena. Examples include the measurement of extremely small magnetic fields with subfluxon sensitivity by electron wave interferometry, subnanometer wavefront evaluation of projection optics for extreme UV lithography, the detection of sub-Ångstrom distortion of a crystal lattice, and the measurement of ultrashort optical pulses in the femotsecond to attosecond range, which show how the advantages of FFA are exploited in these cutting edge applications.

Measurement of high time-bandwidth pulses on a chip with SPIDER

We develop a method capable of characterizing both the amplitude and phase of ultrafast optical pulses with the aid of a synchronized incoherently-related clock pulse based on a novel variation of SPIDER. It exploits degenerate four-wave-mixing and its design is amenable for full ?on chip? signal characterization. By implementing our method in a CMOS compatible waveguide, we measure pulses with 1THz, and up to 100ps pulsewidths. Our novel reconstruction algorithm that we call Fresnel-Limited Extraction Procedure (FLEA), yields a time-bandwidth product (TBP)>100. Full Text: PDF References R. Trebino, "Frequency Resolved Optical Gating: the Measurement of Ultrashort Optical Pulses", (Kluwer Academic, 2002) [CrossRef] I. A. Walmsley and C. Dorrer, "Characterization of ultrashort electromagnetic pulses", Adv. Opt. Photon. 1, 308-437 (2009) [CrossRef] Nature Photonics Workshop on the future of optical communication,Tokyo, Oct. 2007. M. A. Foster et al.,"Silicon-chip-based ultrafast optical oscilloscope", Nature 456, 81-84 (2008) [CrossRef] E. K. Tien, X. Z. Sang, F. Qing, Q. Song, and O. Boyraz., "Ultrafast pulse characterization using cross phase modulation in silicon", Appl. Phys. Lett. 95, 051101 (2009) [CrossRef] A. Pasquazi et al.,"Sub-picosecond phase-sensitive optical pulse characterization on a chip", [CrossRef] C. Iaconis and I.A. Walmsley,"Spectral phase interferometry for direct electric-field reconstruction of ultrashort optical pulses", Opt. Lett., 23, 792-794 (1998) [CrossRef] L. Gallmann et al.,"Characterization of sub-6-fs optical pulses with spectral phase interferometry for direct electric-field reconstruction", Opt. Lett., 24, 1314-1316 (1999) [CrossRef] C. Dorrer et al.,"Single-shot real-time characterization of chirped-pulse amplification systems by spectral phase interferometry for direct electric-field reconstruction", Opt. Lett., 24, 1644-1646 (1999) [CrossRef] D. Keusters et al.,"Relative-phase ambiguities in measurements of ultrashort pulses with well-separated multiple frequency components", J. Opt. Soc. Am. B, 20, 2226-2237 (2003) [CrossRef] M. Hirasawa et al.,"Sensitivity improvement of spectral phase interferometry for direct electric-field reconstruction for the characterization of low-intensity femtosecond pulses", Appl. Phys. B, 74, S225-S229 (2002) [CrossRef] J. Wemans, G. Figueira, N. Lopes and L. Cardoso,"Self-referencing spectral phase interferometry for direct electric-field reconstruction with chirped pulses", Opt. Lett., 31, 2217-2219 (2006)Self-referencing spectral phase interferometry for direct electric-field reconstruction with chirped pulses [CrossRef] M. Peccianti et al.,"Subpicosecond optical pulse compression via an integrated nonlinear chirper", Opt. Express, 18, 7625-7633 (2010) [CrossRef] A. Pasquazi et al.,"All-optical wavelength conversion in an integrated ring resonator", Opt. Express 18, 3858-3863 (2010) [CrossRef]

Two-dimensional spectral shearing interferometry resolved in time for ultrashort optical pulse characterization

We present a new scheme for coherent measurement of ultrashort optical pulses that relies on spectral shearing interferometry combined with all-optical time gating. The spectral phase is encoded along a temporal coordinate resulting in a two-dimensional (2D) self-referenced and self-calibrating set of data. The method works without time delay between the two interfering signals. The pulse amplitude and phase are reconstructed with a high signal-to-noise ratio using a direct algorithm that applies a Fourier transform (FT) to the 2D recorded interference pattern. Characterization of low-energy, high-repetition-rate femtosecond pulses of various shapes and validation of a single-shot operation are reported.

Fringe-free spectral phase interferometry for direct electric-field reconstruction

A novel spectral phase interferometry reconstruction for ultrashort optical pulse measurement with high accuracy is presented to overcome the shortcomes of conventional SPIDER. The measured pulse and its two chirped and delayed replicas are mixed synchronously to generate a fringe-free interference pattern. By introducing a suitable small delay into the interference pattern the spectral phase of the measured pulse is retrieved directly and uniquely without using Fourier transformation. This technique is capable of characterizing pulses with long duration or/and complex phase structure.

Real-time intuitive spectrogram measurement of ultrashort optical pulses using two-photon absorption in a semiconductor

Real-time acquisition of intuitive spectrograms based on twophoton absorption frequency-resolved optical gating is demonstrated in a wavelength range around 1500 nm using an InP crystal for a two-photon absorption medium. Rapid wavelength-delay scanning, based on a counterrotating spectrometer mirror synchronized with a delay stage, is introduced and incorporated with lock-in detection for the real-time spectrogram acquisition. It is shown that the frequency marginal and average delay time of acquired spectrograms provide the spectral intensity and group delay time of optical pulses under test. This allows the direct and rapid measurement of the magnitude and phase of ultrashort optical pulses in the spectral domain without using pulse retrieval algorithms to reconstruct the pulse shapes.

Method of Ultrashort Optical Pulse Measurement.

This paper describes the principle of ultra-short optical pulse measurement including novel measuremet methods that have recently been developed. The SHG auto-correlation method is most widely used to estimate the short optical pulse width. However, two-photon absorption in LED's and photodiodes has been applied to generate the nonlinear correlation signal instead of SHG, and has revealed remarkable performance in the short pulse measurement. On the other hand, the cross-correlation method such as the optical sampling method has been introduced into the measurement of transient response of optical devices and the pulse pattern measurement in ultra-high speed optical transmission systems. The reconstruction of the waveform and phase from the measured correlation signal is also an important problem. This paper deals with the FROG (Frequency Resolved Optical Gating) developed for this purpose.

Measurement of ultrashort optical pulses by third-harmonic generation

Interferometric and intensity autocorrelations by third-harmonic generation for the measurement of ultrashort optical pulses are demonstrated. The third-harmonic signal is generated by tight focusing of the ultrashort pulses upon the surface of an ordinary glass slide, replacing the high-optical-quality nonlinear crystals used in conventional second-harmonic generation measurements. The method is shown to be applicable to real-time measurements.

Multiple- and single-shot autocorrelator based on two-photon conductivity in semiconductors

Two-photon-induced conductivity has been observed in Si and GaAsP photodiodes and in a CdS photo-conductive cell at room temperature and applied to the ultrashort optical pulse measurement with a simplified Michelson-type arrangement. The efficiency of the two-photon conductivity is found to be 3 x 10(-14)I A/W, where I is the intensity of the incident pulse in watts per squared centimeter. A single-shot pulse-width measurement has also been performed by using a two-dimensional silicon CCD array. Use of these inexpensive photodetectors with nonlinear characteristics has proved to be convenient for intensity correlators because of their instantaneous response to temporal coincidence of optical pulses and ease of optical arrangement.

Femtosecond spectroscopy and transport

Advances in ultrashort optical pulse measurement techniques have opened the way to the investigation of dynamic processes in semiconductors on a time scale previously inaccessible. Pulses as short as 6 femtoseconds have been generated and applied to the study of nonequilibrium processes in semiconductors. New optical electronic measurement techniques have provided the means for investigating transport on a femtosecond time scale. Novel techniques have been developed to study hot electrons in metals in the transient regime. In this contribution I will review these interesting advances and discuss the impact on new understanding in semiconductor physics.

Measurement of ultrashort optical pulses with β-BaB2O4

We have evaluated barium metaborate ( β-BaB2O4) for its use in the measurement of ultrashort optical pulses. Using crystals grown in our laboratory, we have found that pulses as short as 50 fs can be measured accurately with a crystal 1.8 mm thick. The advantages of using barium metaborate rather than potassium dihydrogen phosphate (KDP) or ammonium dihydrogen phosphate (ADP) for autocorrelation measurements are discussed.

Correction to "Effect of group velocity mismatch on the measurement of ultrashort optical pulses via several harmonic generation"

Correction to "Effect of group velocity mismatch on the measurement of ultrashort optical pulses via several harmonic generation"

Real-time measurement of picosecond optical pulses from an InGaAsP diode laser using an ultrafast streak camera with infrared frequency up-conversion

A novel method for real-time measurement of ultrashort optical pulses generated from InGaAsP diode lasers at the wavelength of 1.3 μm has been realized by means of an ultrafast streak camera incorporating a frequency up-conversion technique with a LiIO3 crystal pumped by a Q-switched neodymium: yttrium aluminum garnet (Nd:YAG) laser at 1.064 μm. The optical pulse from an InGaAsP double-channel planar buried heterostructure (DC-PBH) diode laser operated by a short pulse current of 1-ns duration was measured to have a full width at half-maximum (FWHM) of approximately 28 ps by single shot scanning with the temporal resolution of 8 ps. Using a 15-mm-long LiIO3 crystal and 500-W peak power of the pumping laser pulse focused at 400 μm in diameter, the up-conversion efficiency and minimum detectable peak power of the diode laser pulse at 1.3 μm were estimated to be approximately 0.65% and 1 mW, respectively. This technique can be widely utilized for real-time detection of ultrashort optical pulses in the wavelength range beyond 1–10 μm or more.

Effect of group velocity mismatch on the measurement of ultrashort optical pulses via second harmonic generation

The use of second harmonic generation as a technique for optical pulse width measurements is analyzed to determine the effects of both phase velocity and group velocity mismatch between fundamental and second harmonic fields. An expression for the time average second harmonic energy, which except for special cases differs from the intensity autocorrelation function, is derived. For Type I phase matching, the measurement yields an apparent correlation width which can be either shorter or longer than the actual intensity correlation width, depending on the specific pulse shape. When the group velocity mismatch is nonzero, the measurement becomes sensitive to the phase matching condition. Two special pulse shapes for which the measurement is independent of group and phase velocity mismatch are the Gaussian and the single-sided exponential.

Generation and Measurement of Ultrashort Optical Pulses from Semiconductor Diode Lasers

Generation and Measurement of Ultrashort Optical Pulses from Semiconductor Diode Lasers

Measurement of ultrashort optical pulses by two-photon photoconductivity techniques

Two-photon conductivity in GaAs and CdS0·5Se0·5 were investigated with modelocked Nd:glass laser pulse excitation, with a view to determine their suitability for picosecond pulsewidth measurement. The contrast ratio using GaAs as twophoton conductor was 1.8 and it increased to 2.4 when CdS0·5Se0·5 was used. The improved contrast ratio in the case of CdS0·5Se0·5 was partly due to the improved resolution of the crystal (2 ps) and partly due to the extended square-law region.