For many applications that involve measuring ultrafast optical phenomena, the streak camera is the device of choice because of its excellent time resolution, its high sensitivity, the possibility to simultaneously measure lifetimes and spectra, and because it can capture the temporal dynamics in a single shot. Nevertheless, to obtain a good time resolution, often narrow slits have to be employed that restrict the image source area and, therefore, limit the light collection efficiency in the experiment. For some applications, it is therefore challenging to find an acceptable balance between the time resolution and signal-to-noise ratio. To overcome this limitation, we have devised the propagation synchronous integration principle for the streak camera, in which an effective spatio-dependent time-shift in the excitation of a sample is introduced and counteracted by the streak sweep, thereby effectively allowing for an increased image source area while maintaining the optimal time resolution. Using the Optronis streak camera with tunable streak sweep and large (1 mm) photocathode width, we could achieve a sevenfold increase in light collection efficiency without affecting the time resolution. Furthermore, we were also able to achieve an 11-fold increase in light collection at the cost of a 26% decrease in the time resolution.

This work presents a new burst mode CMOS image sensor in 0.35 mu m SiGe BiCMOS technology that can achieve a pixel rate of 1 TS/s. The sensor employs a novel integrated Streak architecture that includes a vector of 200 integrated photodiodes, each connected to a wideband transimpedance amplifier, and a 200 points deep analogue on-chip memory for burst imaging. Placing the pixel electronics next to the photodector results in a high fill factor of 84 %. The circuit has a closed loop delay generator that allows sampling speeds from 50 mu s to 200 ps, resulting in the largest range recorded for a monolithic CMOS sensor to date. The sensor features a post-trigger functionality to avoid synchronization issues during event recording. For the recording of repetitive events, the sensor has a new accumulation mode to enhance the signal to noise ratio (SNR) by reducing the bandwidth of the sample & hold circuit, thus allowing the SNR to be increased by a factor of sqrt(10) per decade. The state-of-the-art time resolution makes this sensor ideal for observing subnanosecond events. It finds applications in various fields, including fluorescence metrology, time-resolved spectroscopy, optical tomography, laser Doppler velocimetry, and detonics.

we present the very first fully integrated streak camera realized with a specific ultrafast CMOS sensor. This sensor is composed of a vector of 200 photodiodes and each photodiode signal is sampled on an on-chip memory that can record 200 samples. It results on a sampling matrix of 200x200 samples that stores the values of the slit at the different sampling time. The sampling rate can be set up to 4 GS/s, i.e., the maximal total sampling rate of the matrix is 800 GS/s. It is possible to post trigger the streak camera and to extract the past samples.

Streak cameras are now reaching sub-picosecond temporal resolution. In cumulative acquisition mode, this resolution does not entirely rely on the electronic or the vacuum tube performances but also on the light source characteristics. The light source, usually an actively mode-locked laser, is affected by phase and amplitude noises. In this paper, the theoretical effects of such noises on the synchronization of the streak system are studied in synchroscan and triggered modes. More precisely, the contribution of band-pass filters, delays, and time walk is ascertained. Methods to compute the resulting synchronization jitter are depicted. The results are verified by measurement with a streak camera combined with a Ti:Al2O3 solid state laser oscillator and also a fiber oscillator.

Streak camera systems are most of the time triggered by short light pulses affected by amplitude noise. This implies jitter on the trigger signal which degrades the temporal resolution. A Constant Fraction Discriminator (CFD) provides a triggering solution which is immunized to this type of noise. A new CFD design approach is described in this work. With state-of-the-art discrete components in terms of high speed electronics, the designed CFD reaches an ultra-low jitter level. Using a heterodyne measurement technique, the phase noise study reveals a 120 fs rms jitter at fixed light power amplitude. The time walk of the system is evaluated to ±10 ps for a 1:10 optical power ratio. The CFD also offers two distinct outputs for the streak camera: the first provides a square wave signal for the single shot mode and the second provides a high frequency sinusoid for the synchroscan mode.

Streak cameras are typically designed by a top-down concept. Top of the concept is the streak tube technology that is selected to obtain best measurement results for the application specific requirements. As streak tubes vary in physical dimensions and electrical characteristics, streak cameras are designed with different mechanical housings, tube polarisation electronics, sweep units and communication interfaces. This approach leads to a large number of individual and consequently expensive streak cameras. A new streak camera concept allows the integration of different streak tubes to offer more flexibility for specific application requirements but also general needs. The mechanical design provides interfaces for various sweep units, image intensifier units or electro-mechanical shutter devices. The concept supports a modular configuration using plug-in sweep units today only realised with standard streak cameras. Combined with standardised electrical interfaces, the streak camera can be configured for various applications without redesign. This additionally allows the adaptation to vacuum and other demanding environmental conditions.

The temporal resolution of a synchroscan streak camera is mainly limited by the intrinsic tube resolution, the laser pulse width and the synchronization jitter between the camera and the laser source. Studies show that laser phase noise is localised principally at low frequency. A previous system was designed in order to eliminate the very low frequency jitter. The system allows the streak camera to accumulate a signal during over a long period (several hours) without significant temporal resolution degradation. In order to work properly, this system use a laser reference directly coupled to the streak camera on the top of the photocathode. The localisation of this laser reference spot is locked at a predefined position and then, the temporal axis of the streak camera image is locked. To allow this control, the software changes the phase between the deflection plate voltage and the synchroscan signal. The resolution obtained was about 2 ps Full Width at Half Maximum (FWHM) which is the best resolution available in the accumulation mode and this can be achieved whatever the accumulation time. In this paper, we describe an upgrade of this system which uses the laser reference information to accumulate the different frames after a retiming. It calculates the centre of gravity (COG) of the laser reference, shifts the image on the temporal axis with a sub-pixel resolution to place this COG to a predefined position. Then the frames are accumulated. By this way, the inter frame jitter is reduced. This system benefits from the very high temporal resolution of the streak camera to make to correction so that it can be very efficient. In photon counting, the temporal resolution with this system is improved to a value of 1,5 ps FWHM. With a signal to noise ratio of about 1000 the acquisition time is 35 minutes.

In this article, we present the drifts phenomena that affect the temporal resolution of a standard synchroscan streak camera and some techniques to correct them in order to enhance the long-term resolution of these cameras. First, we give a comprehensive list of the components of the synchroscan streak camera which are sensitive to temporal and thermal drift: from the trigger circuit to the deflection plate of the tube. The way in which these components make the camera drift is explained and then quantified. A measure of drift realized on two streak cameras at the same time and in the same conditions (the same synchroscan signal) shows that each camera has its own intrinsic and stochastic drift. Second, two techniques to stabilize the camera are then described. The first method stabilizes the phase difference between the synchroscan signal and the deflection plate voltage. The second uses a laser reference trace on the phosphor screen and a digital data processing technique to reach the ultimate stability. The results show that a stabilized camera can be used immediately after it is turned on (due to suppression of the warm-up time) and still has very good temporal resolution even with a long-time exposure (2.4 ps full width at half maximum with a time exposure of 2 h has been achieved). This allows more exploration in the detection of very weak signals.

Different temporal instabilities, which degrade the temporal resolution of a synchroscan streak camera, have been studied. Each of the 3 main components: the laser, the trigger and the streak camera, have their intrinsic instability, thus a degradation of the final temporal resolution is occurred. An internal PLL in the streak camera has been developed in order to improve the temporal resolution. The synchroscan signal is used to lock the phase of the deflection voltage with the laser beam as close as possible. The phase detector has 0 to 360degrees area detection and a jitter lower than 300 fs FWHM integrated from 10 to 600 kHz, allowing sub picoseconds synchronization with the laser beam. The slow drifts, from 0 to 25 Hz, of the phase comparator are cancelled with a laser reference directly inserted in the camera input. By the way of an image processing, the phase command voltage is modified to lock the position of this laser reference. Results show that this stabilized camera can be used immediately after it is turned on (suppression of the warm-up time) and has very good temporal resolution, even with a long time exposure (2.4 ps FWHM with a time exposure of 2 hours has been realised). This allows more exploration in detection of very weak signals.