Experimental quantum imaging distillation with undetected light

Imaging based on the induced coherence effect makes use of photon pairs to obtain information of an object without detecting the light that probes it. While one photon illuminates the object, only its partner is detected, so no measurement of coincidence events are needed. The sought-after object's information is revealed observing a certain interference pattern on the detected photon. Here we demonstrate experimentally that this imaging technique can be made resilient to noise. We introduce an imaging distillation approach based on the interferometric modulation of the signal of interest. We show that our scheme can generate a high-quality image of an object even against noise levels up to 250 times the actual signal of interest. We also include a detailed theoretical explanation of our findings.Comment: 18 pages, 6 figures, and 1 table + 11 pages, 3 figures, and 1 tabl

Perspectives for applications of quantum imaging

Quantum imaging is a multifaceted field of research that promises highly efficient imaging in extreme spectral ranges as well as ultralow‐light microscopy. Since the first proof‐of‐concept experiments over 30 years ago, the field has evolved from highly fascinating academic research to the verge of demonstrating practical technological enhancements in imaging and microscopy. Here, the aim is to give researchers from outside the quantum optical community, in particular those applying imaging technology, an overview of several promising quantum imaging approaches and evaluate both the quantum benefit and the prospects for practical usage in the near future. Several use case scenarios are discussed and a careful analysis of related technology requirements and necessary developments toward practical and commercial application is provided

Quantum holography with undetected light

Holography exploits the interference of light fields to obtain a systematic reconstruction of the light fields wavefronts. Classical holography techniques have been very successful in diverse areas such as microscopy, manufacturing technology, and basic science. Extending holographic methods to the level of single photons has been proven challenging, since applying classical holography techniques to this regime pose technical problems. Recently the retrieval of the spatial structure of a single photon, using another photon under experimental control with a well-characterized spatial shape as reference, was demonstrated using the intrinsically non-classical Hong-Ou-Mandel interference on a beam splitter. Here we present a method for recording a hologram of single photons without detecting the photons themselves, and importantly, with no need to use a well-characterized companion reference photon. Our approach is based on quantum interference between two-photon probability amplitudes in a nonlinear interferometer. As in classical holography, the hologram of a single photon allows retrieving the complete information about the "shape" of the photon (amplitude and phase) despite the fact that the photon is never detected.Comment: 29 pages with 11 figures, submitted to Nature Communication

Experimental analysis on image resolution of quantum imaging with undetected light through position correlations

Image resolution of quantum imaging with undetected photons is governed by the spatial correlations existing between the photons of a photon pair that has been generated in a nonlinear process. These correlations allow for obtaining an image of an object with light that never interacted with that object. Depending on the imaging configuration, either position or momentum correlations are exploited. We hereby experimentally analyse how the crystal length and pump waist affect the image resolution when using position correlations of photons that have been generated via spontaneous parametric down conversion in a nonlinear interferometer. Our results support existing theoretical models for the dependency of the resolution on the crystal length. In addition, we probe the resolution of our quantum imaging scheme for varying pump waists over one order of magnitude. This analysis reveals the intricate dependency of the resolution on the strength of the correlations within the biphoton states for parameter combinations in which the crystal lengths are much larger than the involved photon wavelengths. We extend the existing models in this parameter regime to properly take nontrivial effects of finite pump waists into account and demonstrate that they match the experimental results.Comment: 28 pages, 9 figure

Miniaturized frequency doubled DPSS laser soldered for space applications

This master thesis presents the research performed to reach the optimum assembling technique for the miniaturized green laser for the ESA Exomars space mission. The strong requirements on optical performance of the laser, in combination with the space resistance needs, make a challenge to assemble this laser. The objective of this master thesis is to demonstrate that assembling the laser using the solderjet soldering technology studied and developed by Fraunhofer IOF is the solution for the laser to meet requirements on spectrum repeatability and stability, as well as satisfying the strict optical requirements. The results obtained show the success achieved in both objectives. Stability results obtained are in the range of 0,007nm while requirements allow a wider deviation of less than 0,040nm during 20 minutes. Linewidth of the soldered resonators also meet requirements, being <30pm when optimal condition for the laser operation is found. Moreover, repeatability achieved is a change of 0,004nm of the central wavelength along different days, while glued prototypes showed a bigger change of 0,020nm even during same day tests. In conclusion, the actual phase of the project is finished with the results obtained and the soldered green laser becomes a stronger candidate for next Exomars project validation phases

Miniaturized frequency doubled DPSS laser soldered for space applications

This master thesis presents the research performed to reach the optimum assembling technique for the miniaturized green laser for the ESA Exomars space mission. The strong requirements on optical performance of the laser, in combination with the space resistance needs, make a challenge to assemble this laser. The objective of this master thesis is to demonstrate that assembling the laser using the solderjet soldering technology studied and developed by Fraunhofer IOF is the solution for the laser to meet requirements on spectrum repeatability and stability, as well as satisfying the strict optical requirements. The results obtained show the success achieved in both objectives. Stability results obtained are in the range of 0,007nm while requirements allow a wider deviation of less than 0,040nm during 20 minutes. Linewidth of the soldered resonators also meet requirements, being <30pm when optimal condition for the laser operation is found. Moreover, repeatability achieved is a change of 0,004nm of the central wavelength along different days, while glued prototypes showed a bigger change of 0,020nm even during same day tests. In conclusion, the actual phase of the project is finished with the results obtained and the soldered green laser becomes a stronger candidate for next Exomars project validation phases

Miniaturized frequency doubled DPSS laser soldered for space applications

This master thesis presents the research performed to reach the optimum assembling technique for the miniaturized green laser for the ESA Exomars space mission. The strong requirements on optical performance of the laser, in combination with the space resistance needs, make a challenge to assemble this laser. The objective of this master thesis is to demonstrate that assembling the laser using the solderjet soldering technology studied and developed by Fraunhofer IOF is the solution for the laser to meet requirements on spectrum repeatability and stability, as well as satisfying the strict optical requirements. The results obtained show the success achieved in both objectives. Stability results obtained are in the range of 0,007nm while requirements allow a wider deviation of less than 0,040nm during 20 minutes. Linewidth of the soldered resonators also meet requirements, being <30pm when optimal condition for the laser operation is found. Moreover, repeatability achieved is a change of 0,004nm of the central wavelength along different days, while glued prototypes showed a bigger change of 0,020nm even during same day tests. In conclusion, the actual phase of the project is finished with the results obtained and the soldered green laser becomes a stronger candidate for next Exomars project validation phases

Insights of the Qualified ExoMars Laser and Mechanical Considerations of Its Assembly Process

1960 is the birth year of both the laser and the Mars exploration missions. Eleven years passed before the first successful landing on Mars, and another six before the first rover could explore the planet&#8217;s surface. In 2011, both technologies were reunited with the first laser landing on Mars as part of the ChemCam instrument, integrated inside the Curiosity Rover. In 2020, two more rovers with integrated lasers are expected to land on Mars: one through the National Aeronautics and Space Administration (NASA) Mars 2020 mission and another through the European Space Agency (ESA) ExoMars mission. The ExoMars mission laser is one of the components of the Raman Spectrometer instrument, which the Aerospace Technology National Institute of Spain (INTA) is responsible for. It uses as its excitation source a laser designed by Monocrom and manufactured in collaboration with the Fraunhofer Institute for Applied Optics and Precision Engineering (IOF). In this paper, we present for the first time the final flight module laser that has been installed in the rover&#8217;s onboard laboratory and validated to be shipped to Mars in 2020. Particular emphasis is given to mechanical considerations and assembly procedures, as the ExoMars laser assembly has required soldering techniques in contrast to the standard adhesive technologies used for most laser assembly processes in order to fulfill the environmental and optical requirements of the mission

Perspectives for Applications of Quantum Imaging

Quantum imaging is a multifaceted field of research that promises highly efficient imaging in extreme spectral ranges as well as ultralow‐light microscopy. Since the first proof‐of‐concept experiments over 30 years ago, the field has evolved from highly fascinating academic research to the verge of demonstrating practical technological enhancements in imaging and microscopy. Here, the aim is to give researchers from outside the quantum optical community, in particular those applying imaging technology, an overview of several promising quantum imaging approaches and evaluate both the quantum benefit and the prospects for practical usage in the near future. Several use case scenarios are discussed and a careful analysis of related technology requirements and necessary developments toward practical and commercial application is provided