Conventional Streak Camera Research Articles

An ultrafast camera films light at light speed

Exploiting a strategy known as compressed sensing, the camera can capture video at 100 billion frames per second.

Numerical Analysis of Sampling Streak Camera for Higher Temporal Resolution Operation

The streak camera is one of the highest temporal resolution measurement devices for luminous phenomena, and the sampling streak camera is its advanced device for image measurements in time domain. In general, the temporal resolution of the sampling streak camera is less than that of the conventional streak camera due to complicated electron motion in the device. For improvement of the sampling streak camera for higher temporal resolution of order of pico-second, understanding of physical phenomena in this device is essential and then numerical analysis play an important role. This paper presents a numerical analysis method of the sampling streak camera based on self-consistent simulation of electrostatic field and relativistic electron beam motion by using particle-in-cell (PIC) method. It is predicted from the numerical simulation that higher temporal resolution operation of the sampling streak camera will cause serious inaccuracy in phase information due to the space charge effects.

Streak camera in standard (Bi)CMOS (bipolar complementary metal-oxide-semiconductor) technology

The conventional streak camera (CSC) is an optoelectronic instrument that captures the spatial distribution as a function of time of an ultra high-speed luminous phenomenon with picosecond temporal resolution and a typical spatial resolution of several tens of micrometers. This paper presents two tubeless streak camera architectures called MISC (matrix integrated streak camera) and VISC (vector integrated streak camera), which replicate the functionality of a CSC on a single CMOS chip. The MISC structure consists of a lens, which spreads the photon flux on the surface of a specific pixel array-based (Bi)CMOS sensor. The VISC architecture is based on a sensor featuring a single column of photodetectors, where each element is coupled to a front-end and a multi-sampling and storage unit. In this case the optical objective used in front of the sensor focuses the luminous event on the several tens of micrometers wide photosensitive column. For both architectures, the spatial resolution is linked to the size of the photodetector and the temporal resolution is determined by the bandwidths of the photodetectors and the signal conditioning electronics. The capture of a 6 ns full width at half maximum 532 nm laser pulse is reported for two generations of MISC and a first generation of VISC.

X-ray monochromatic high-speed imager for FIREX fast ignition research

A novel x-ray imager, consisting of two toroidally bent Bragg crystals and a 2D image sampler using a conventional x-ray streak camera, has been demonstrated for use in fast ignition resaerch. Sequential and 2D monochromatic x-ray images of laser-imploded core plasma were successfully obtained with a temporal resolution of 20 ps, a spatial resolution of 31 μm, and a spectral resolution of over 200, simultaneously.

Single-shot terahertz-field-driven X-ray streak camera

A few-femtosecond X-ray streak camera has been realized using a pump–probe scheme that samples the transient response of matter to ionizing soft X-ray radiation in the presence of an intense synchronized terahertz field. Borrowing its concept from attosecond metrology, the femtosecond X-ray streak camera fills the gap between conventional streak cameras with typical resolutions of hundreds of femtoseconds and streaking techniques operating in the sub-femtosecond regime. Its single-shot capability permits the duration and time structure of individual X-ray pulses to be determined. For several classes of experiments in time-resolved spectroscopy, diffraction or imaging envisaged with novel accelerator- and laser-based short-pulse X-ray sources this knowledge is essential, but represents a major challenge to X-ray metrology. Here we report on the single-shot characterization of soft X-ray pulses from the free-electron laser facility FLASH. A streak camera for characterizing the ultrashort X-ray pulses produced by a free-electron laser is reported. The scheme has a single-shot capability, a resolution of a few femtoseconds and is expected to become a useful tool for X-ray metrology, including experiments involving time-resolved spectroscopy and imaging.

A novel compact high speed x-ray streak camera (invited)

Conventional in-line high speed streak cameras have fundamental issues when their performance is extended below a picosecond. The transit time spread caused by both the spread in the photoelectron (PE) "birth" energy and space charge effects causes significant electron pulse broadening along the axis of the streak camera and limits the time resolution. Also it is difficult to generate a sufficiently large sweep speed. This paper describes a new instrument in which the extraction electrostatic field at the photocathode increases with time, converting time to PE energy. A uniform magnetic field is used to measure the PE energy, and thus time, and also focuses in one dimension. Design calculations are presented for the factors limiting the time resolution. With our design, subpicosecond resolution with high dynamic range is expected.

Terahertz pulse measurement with an optical streak camera

Incorporating an electro-optic modulator with a conventional optical streak camera extends the spectral range of the streak camera from the optical region (UV, visible, and near-IR) to the terahertz region (far-IR and millimeter-wave) with a minimum modification. We demonstrate the temporal measurement of freely propagating terahertz pulses with single-shot capability.

Demonstration of a far-infrared streak camera

An atomic infrared (IR) streak camera is demonstrated that operates in the mid- and far-infrared (/spl lambda/=5-85 /spl mu/m), well beyond the long wavelength cutoff of conventional streak cameras. The temporal and spectral characteristics of the streak camera are determined using the FELIX free-electron laser as the IR light source. The temporal resolution of the streak camera was found to be as short as 1.2 ps. The high sensitivity of the streak camera is demonstrated by single-shot characterization of the IR pulses of FELIX.

Streak camera operating in the mid infrared

An atomic streak camera has been constructed that operates from the near to the far infrared. The photocathode used in conventional streak cameras for the conversion of photons to electrons has been replaced by gas-phase atoms in a Rydberg state. The low binding energy of the electron in a Rydberg atom combined with the large photoionization cross section of a Rydberg atom makes Rydberg atoms suitable for use in an infrared streak camera. Operation of the streak camera is demonstrated at 2.6 microm, well beyond the spectral range of any conventional streak camera.

Exact forward scattering of a CO2 laser beam from a relativistic plasma wave by time resolved frequency mixing in AgGaS2

In the UCLA plasma beat wave accelerator, a high intensity two frequency CO2 laser (λ1=10.6 μm, λ2=10.3 μm) is used to drive a large amplitude relativistic plasma wave. The plasma wave acts as a moving phase grating and scatters the incident pump waves into Stokes and anti-Stokes sidebands (ω1−ωp, ω2+ωp). The observation of these sidebands in the forward direction confirms the presence of the relativistic plasmon, and also gives an estimate of the amplitude–length product (n1/n0×L) of the wave. Since the Stokes and anti-Stokes signals are picosecond pulses at 10.9 and 10.0 μm, respectively, this light cannot be time resolved directly on a conventional detector or streak camera. The forward scattered light can be analyzed, however, by mixing the 10 μm light with visible light from a laser diode (670 nm) in a nonlinear crystal (AgGaS2) to produce frequency shifted light at 630 nm. The intensity of the 630 nm light is proportional to the product of the intensities of the two incident laser pulses, and can be time resolved on a streak camera. Experimental results for the plasma wave amplitude, spatial length, and temporal length are shown.

Far-infrared streak camera

Abstract The concept of a streak camera operating throughout the far-infrared (1–100 μm) is discussed. The photocathode, used in a conventional streak camera to create an electron pulse, is replaced by gas phase atoms in a highly excited state, a Rydberg state. Rydberg electrons have an extremely low binding energy (work function) combined with a high FIR photo-ionization cross section. A streak camera based on an atomic-vapour photocathode is demonstrated in the visible and a sub-picosecond resolution is obtained.

A proposal for a radio-frequency-based streak camera with time resolution less than 100 fs

The authors propose a novel idea for a streak camera whose time resolution is lower than 100 fs. The method replaces the high-voltage sweep component of a conventional streak camera by a TM110-mode RF cavity, which performs a transverse circular sweep of the electron bunch in the streak tube through a rotating magnetic field. The proposed method also allows one to overcome the problem of triggering, which is a serious limitation of conventional streak cameras.

Use of streak camera for time-resolved photon counting fluorimetry

The use of a conventional streak camera for subnanosecond time-resolved fluorimetry is extended to the single-photon counting regime by utilizing intensified readout of the phosphor. The system achieves the usual key advantages of photon counting, namely single-photon sensitivity, large dynamic range and shot noise limited statistics, but also permits measurements of lower repetition rate and faster time response phenomena, in regimes inaccessible to microchannel plate photomultiplier instrumentation. Pile-up and problems associated with the slow decay and non-uniformity of the response and readout of the stream camera phosphor are discussed.

Gated x-ray pinhole camera for time-resolved 2-D images of laser-driven targets (abstract)

We describe the operation of a multiframe x-ray pinhole camera with time resolutions on the order of 200 ps. This diagnostic provides complementary information to that obtained with a conventional x-ray streak camera. We will describe the characterization of the instrument, obtained optically and electronically, and show x-ray data obtained from laser fusion experiments. This work was performed under the auspices of the U. S. DOE by the Lawrence Livermore National Laboratory under Contract No. W-7405-ENG-48.

Gaseous breakdown studies using a modified image converter streak camera

The temporal and spatial information of gaseous breakdowns occurring from the nanosecond to millisecond time scales are important to the basic understanding and applications of gaseous discharges. A streak camera is an ideal tool for acquiring both time- and space-dependent data simultaneously. However, there are several problems associated with using a conventional streak camera for gaseous breakdown studies. Modifications have been made specifically to solve these problems, while the features of the original streak camera are preserved. A signal overlapping problem has been eliminated by extending the dead time to 70 ms. Streak camera response times have been minimized by adjusting the bias voltages. One streak range has been extended to 7 ms to cover the entire event of a gaseous discharge. The modifications and experimental evaluation of the modified streak camera will be presented.

Picosecond framing technique using a conventional streak camera

A picosecond digitally-restored image-dissected framing method involving a conventional streak camera and new computer software is described. The preliminary result gave 5 frames with an exposure time of 13 ps and spatial resolutions of 2 1p/mm on the screen and 6 1p/mm on the photocathode. A framing speed of 7.7×1010 frames/s for frame sizes of 15×15 mm has been demonstrated.

Image Converter High-Speed Photography with 10^−9–10^−14 sec Time Resolution

The rapid progress in image tube development during recent years has greatly extended the potentialitie of high-speed photography which surpassed even the highly refined oscilloscopic method in time resolution and was made able to record nonrepeated short-duration processes emitting few light quanta. The new situation in high-speed photography has arisen due to the advent of cascaded image converters which have the advantages of ultimate time resolution (down to 10−14 sec), ultimate light efficiency (single light quanta being easily recorded), and high signal-to-noise ratio due to information communication via images consisting of 105–106 resolved elements. The ultra high-speed photography technique using a fast electric field sweep of the electronic image in image converters is called the electron-optical chronography. It has been applied to study spark discharges and secondary emission electron pulses with experimental time resolutions of 10−12–10−13 sec, which greatly exceeded that of conventional streak cameras, Kerr cells, oscilloscopes, and coincidence circuits. The purpose of the present paper is to analyze the fundamental time-resolution limitations of conventional short-time research instruments, to consider the ultimate performance limits of the electron-optical chronography, to describe special image tubes for short-time research, and to review their applications in experimental physics.