Related papers: Active sub-Rayleigh alignment of parallel or antip…
A novel method capable of delivering relative optical path length metrology with nanometer precision is demonstrated. Unlike conventional dual-wavelength metrology which employs heterodyne detection, the method developed in this work…
A method for absolute calibration of a photon-number resolving detector producing analog signals as the output is developed using a twin beam. The method gives both analog-to-digital conversion parameters and quantum detection efficiency…
We have demonstrated several inexpensive methods which can be used to measure the deflection angles of prisms with microradian precision. The methods are self-referenced, using various reversals to achieve absolute measurements without the…
Aberration-corrected optics have made electron microscopy at atomic-resolution a widespread and often essential tool for nanocharacterization. Image resolution is dominated by beam energy and the numerical aperture of the lens ({\alpha}),…
A radar system emits probing signals and records the reflections. Estimating the relative angles, delays, and Doppler shifts from the received signals allows to determine the locations and velocities of objects. However, due to practical…
No imaging apparatus can produce perfect images: spatial resolution is limited by the Rayleigh diffraction bound that is a consequence of the imager's finite spatial extent. We show some N-photon strategies that permit resolution of details…
We develop a theoretical model for calibrating the absorption imaging of cold atoms under high magnetic fields. Comparing to zero or low magnetic fields, the efficiency of the absorption imaging becomes lower while it requires an additional…
Synchronising ultra-short (~fs) and focussed laser pulses is a particularly difficult task, as this timescale lies orders of magnitude below the typical range of fast electronic devices. Here we present an optical technique that allows for…
A parabolic monocapillary X-ray lens (PMXRL) is designed to effectively constrain a laboratory point X-ray source into a parallel beam. A square-shaped lead occluder (SSLO) is used to block direct X-rays in the PMXRL. To design the PMXRL,…
We report on a new technique to split an atomic beam coherently with an easily adjustable splitting angle. In our experiment metastable helium atoms in the |{1s2s}^3S_1 M=1> state diffract from a polarization gradient light field formed by…
We extend the technique of multiplex coherent Raman spectroscopy with two femtosecond mode-locked lasers to oscillators of a pulse repetition frequency of 1 GHz. We demonstrate spectra of liquids, which span 1100 cm$^{-1}$ of Raman shifts.…
Rydberg atom,which exhibits a strong response to weak electric(E) fields,is regarded as a promising atomic receiver to surpass sensitivity of conventional receivers. However, its sensitivity is strongly limited by the noise coming from both…
Wavefront distortions are a leading source of systematic uncertainty in light-pulse atom interferometry, limiting absolute measurements of gravitational acceleration at the 30 nm/s$^2$ level. Here, we demonstrate in situ spatially resolved…
We show that the frequency of a Raman laser is highly correlated or anti-correlated with the frequency of the Raman pump laser, depending on whether the dispersion experienced by the Raman laser is positive or negative. For a subluminal…
Correlation radiometers make true differential measurements in power with high accuracy and small systematic errors. This receiver architecture has been used in radio astronomy for measurements of continuum radiation for over 50 years; this…
Aberration correctors are essential elements for achieving atomic resolution in state-of-the-art electron microscopes. Conventional correctors are based on a series of multipolar electron lenses, but more versatile alternatives are…
We establish the multiparameter quantum Cram\'er-Rao bound for simultaneously estimating the centroid, the separation, and the relative intensities of two incoherent optical point sources using alinear imaging system. For equally bright…
Angle-resolved (AR) RABBIT measurements offer a high information content measurement scheme, due to the presence of multiple, interfering, ionization channels combined with a phase-sensitive observable in the form of angle and time-resolved…
We report ultra-stable locking of a commercially available extended cavity diode laser to a vibration-insensitive high finesse Fabry-Perot cavity. A servo bandwidth of 2 MHz is demonstrated. The absolute stability of the diode laser after…
We have measured twelve transition frequencies of the antiprotonic helium atom (pbar-He+) with precisions of 0.1--0.2 ppm using a laser spectroscopic method. The agreement between the experiment and theories was so good that we can put a…