
Quantum Engineering of Light
Prof. Dr. Juan P. Torres
- Activities:
We generate, tailor, use and detect new types of classical and quantum light for:
- Exploring fundamental aspects of quantum theory and
- Enabling or enhancing the implementation of applications that might require specific types of quantum or classical light, especially in communications and high-resolution probing and imaging.
We consider with special interest new ways of tailoring the frequency and spatial entanglement of paired photons, through the implementation of new configurations in spontaneous parametric down conversion schemes. The spatial shape of photons is used for generating qudits with properties on demand (spatial quantum engineering).
Two well-equipped labs with four Optical Tables, CW and pulsed lasers at different wavelengths, Single Photon Counting Modules at different frequency bands, nonlinear crystals, monochromators, spectrometers and all necessary optical and electronic equipment.
- Collaborations:
- Prof. Bahaa Saleh, CREOL, Orlando, Florida (USA)
- Prof. Malvin C. Teich, Boston University, Boston (USA)
- Dr. Fabio Sciarrino, University of Rome, Roma (Italy)
- Prof. J. H. Eberly, University of Rochester, Rochester (USA)
- Dr. Alfred U’Ren, Universidad Nacional Autonoma de Mexico (UNAM), Mexico DF (Mexico)
Contact: This email address is being protected from spambots. You need JavaScript enabled to view it.
Quantum Engineering of Light
Prof. Dr. Juan P. Torres


- Group Leader
- Prof. Dr. Juan P. Torres
- Postdoctoral Researchers
- Dr. Marcello Henrique Marques Passos
- PhD Students
- Gerard Jiménez Machado
- Daniel Urrego
- Arturo Villegas
- Undergrad & Postgrad Students
- Jesús Díaz Ferrer
- Helena Kirchner Sala
- Anna Migó
- Jaume Villasante Cánovas
- Former Group Members
- Sergio Vladimir Barreiro, Visiting scientist
- Yana Stoimenova Deyanova, PhD student
- Nina Fleischmann, Research engineer
- Noelia González, PhD student
- Martin Hendrych, Visiting scientist
- Nathaniel Il Placido Hermosa, Research fellow
- Dalibor Javurek, Visiting scientist
- Yasser Jerónimo, Visiting scientist
- Roberto de Jesús León, PhD student
- Dorilian Lopez Mago, Visiting scientist
- Radek Machulka, Visiting scientist
- Job Mendoza, Postdoctoral researcher
- Michal Micuda, Visiting scientist
- Gabriel Molina, Research fellow
- Eleonora Nagali, Visiting scientist
- Clara Inés Osorio, PhD student
- Eugene Polzik, Invited professor
- Carmelo Guadalupe Rosales, PhD student
- Luís José Salazar Serrano, PhD student
- Xiaojuan Shi, PhD student
- Jiri Svozilik, Visiting scientist
- Reddeppa Thanneeru, PhD student
- Adam Vallés, PhD student
- Verónica Vicuña Hernández, Postdoctoral researcher
- Karen Patricia Volke, Visiting professor
Quantum Engineering of Light
Prof. Dr. Juan P. Torres

- Regular Papers
- Frequency-correlation requirements on the biphoton wave function in an induced-coherence experiment between separate sources Phys. Rev. A 102, 053711 (2020)
- Optical coherence tomography with a nonlinear interferometer in the high parametric gain regime Appl. Phys. Lett. 117, 094002 (2020)
- Quantum-inspired Fredkin gate based on spatial modes of light Opt. Express 28, 12661-12674 (2020)
- Random number generation by coherent detection of quantum phase noise Opt. Express 28, 5538 (2020)
- Temperature-controlled entangled-photon absorption spectroscopy Phys. Rev. Lett. 123, 023601 (2019)
- Knotting fractional-order knots with the polarization state of light Nature Photon. 13, 569-574 (2019)
- Hong-Ou-Mandel interferometry on a biphoton beat note npj Quantum Inf. 5, 43 (2019)
- Technique for generating periodic structured light beams using birefringent elements Opt. Express 26, 28938 (2018)
- Space QUEST mission proposal: experimentally testing decoherence due to gravity New J. Phys. 20, 063016 (2018)
- Optical sectioning in induced coherence tomography with frequency-entangled photons Phys. Rev. A 97, 023824 (2018)
- Steering and switching of soliton-like beams viainteraction in a nanocolloid with positive polarizability Opt. Lett. 42, 2487-2490 (2017)
- Roadmap on structured light J. Opt. 19, 013001 (2017)
- A 3D printed toolbox for opto-mechanical components PLoS ONE 12, e0169832 (2017)
- Ultrasensitive interferometric on-chip microscopy of transparent objects Sci. Adv. 2, e1600077 (2016) Highlighted in Nature Photonics
- Constructing entanglement measures for fermions J. Phys. A: Math. Theor. 49, 143001 (2016)
- Frequency conversion of structured light Sci. Rep. 6, 21390 (2016)
- Weak value amplification: a view from quantum estimation theory that highlights what it is and what isn’t Sci. Rep. 5, 19702 (2016)
- Noise-assisted energy transport in electrical oscillator networks with off-diagonal dynamical disorder Sci. Rep. 5, 17339 (2015)
- Revealing hidden coherence in partially coherent light Phys. Rev. Lett. 115, 220501 (2015)
- Measurement of flow vorticity with helical beams of light Optica 2, 1002-1005 (2015)
- Enhancement of the sensitivity of a temperature sensor based on fiber Bragg gratings via weak value amplification Opt. Lett. 40, 3962-3965 (2015)
- Coherent delocalization: views of entanglement in different scenarios Laser Phys. Lett. 12, 085204 (2015)
- Demonstration of a highly-sensitive tunable beam displacer with no use of beam deflection based on the concept of weak value amplification Opt. Express 23, 10097-10102 (2015)
- Tunable beam displacer Rev. Sci. Instrum. 86, 033109 (2015)
- Generation of tunable entanglement and violation of a Bell-like inequality between different degrees of freedom of a single photon Phys. Rev. A 90, 052326 (2014)
- Direction-sensitive transverse velocity measurement by phase-modulated structured light beams Opt. Lett. 39, 5415-5418 (2014)
- Importance of excitation and trapping conditions in photosynthetic environment-assisted energy transport J. Phys. Chem. B 118, 10588-10594 (2014)
- Efficient heralding of polarization-entangled photons from type-0 and type-II spontaneous parametric downconversion in periodically poled KTiOPO4 J. Opt. Soc. Am. B 31, 2068-2076 (2014)
- Generation of a tunable environment for electrical oscillator systems Phys. Rev. E 90, 012108 (2014)
- Measuring the translational and rotational velocities of particles in helical motion using structured light Opt. Express 22, 16504-16509 (2014)
- Measurement-based tailoring of Anderson localization of partially coherent light Phys. Rev. A 89, 053808 (2014)
- Hyperentangled photon sources in semiconductor waveguides Phys. Rev. A 89, 023833 (2014)
- Measurement of sub-pulse-width temporal delays via spectral interference induced by weak value amplification Phys. Rev. A 89, 012126 (2014)
- Nanostep height measurement via spatial mode projection Opt. Lett. 39, 299-302 (2014)
- Steering and guiding light with light in a nanosuspension Opt. Lett. 38, 5284-5287 (2013)
- Experimental detection of transverse particle movement with structured light Sci. Rep. 3, 2815 (2013)
- Highly efficient noise-assisted energy transport in classical oscillator systems Phys. Rev. Lett. 110, 218101 (2013)
- Role of the spectral shape of quantum correlations in two-photon virtual-state spectroscopy New J. Phys. 15, 053023 (2013)
- Phase-stable source of polarization-entangled photons in a linear double-pass configuration Opt. Express 21, 11943-11951 (2013)
- Generation of polarization-entangled photon pairs in a Bragg reflection waveguide Opt. Express 21, 10841-10849 (2013)
- Helico-conical optical beams self-heal Opt. Lett. 38, 383-385 (2013)
- Digital coherent receiver for orbital angular momentum demultiplexing Opt. Lett. 38, 241-243 (2013)
- Shaping the ultrafast temporal correlations of thermal-like photons Phys. Rev. Lett. 109, 243905 (2012)
- Implementation of a spatial two-dimensional quantum random walk with tunable decoherence Phys. Rev. A 86, 052327 (2012)
- High spatial entanglement via chirped quasi-phase-matched optical parametric down-conversion Phys. Rev. A 86, 052318 (2012)
- Extracting joint weak values from two-dimensional spatial displacements Phys. Rev. A 86, 053805 (2012)
- Light with enhanced optical chirality Opt. Lett. 37, 3486-3488 (2012)
- Weak interference in the high-signal regime Opt. Express 20, 18869-18875 (2012)
- Weak measurements with orbital-angular-momentum pointer states Phys. Rev. Lett. 109, 040401 (2012)
- Optical communications: Multiplexing twisted light Nature Photon. 6, 420-422 (2012)
- Experimental estimation of the dimension of classical and quantum systems Nature Phys. 8, 588-591 (2012)
- Self-homodyne detection of the light orbital angular momentum Opt. Lett. 37, 2940-2942 (2012)
- Bragg reflection waveguide as a source of wavelength-multiplexed polarization-entangled photon pairs Opt. Express 20, 15015-15023 (2012)
- Fast beam steering with full polarization control using a galvanometric optical scanner and polarization controller Opt. Express 20, 12247-12260 (2012)
- A high-brightness source of polarization-entangled photons optimized for applications in free space Opt. Express 20, 9640-9649 (2012)
- Measurement of the temperature of atomic ensembles via which-way information Phys. Rev. A 85, 033801 (2012)
- Enhancing the sensitivity and robustness of label-free imaging systems via stimulated Raman adiabatic passage New J. Phys. 14, 013018 (2012)
- Engineering nonlinear optic sources of photonic entanglement Prog. Optics 56, 227-331 (2011)
- Optical Doppler shift with structured light Opt. Lett. 36, 4437-4439 (2011)
- True random numbers from amplified quantum vacuum Opt. Express 19, 20665-20672 (2011)
- Flux enhancement of photons entangled in orbital angular momentum Opt. Express 19, 14108-14120 (2011)
- Cancellation of dispersion and temporal modulation with nonentangled frequency-correlated photons Phys. Rev. A 83, 023824 (2011)
- Fast optical source for quantum key distribution based on semiconductor optical amplifiers Opt. Express 19, 3825-3834 (2011)
- Generation of paired photons in a quantum separable state in Bragg reflection waveguides Opt. Express 19, 3115-3123 (2011)
- Design of bright, fiber-coupled and fully factorable photon pair sources New J. Phys. 12, 093027 (2010)
- In-fiber frequency-domain measurement of ultrashort second-order correlations of incoherent light Opt. Lett. 35, 1850-1852 (2010)
- Angular dispersion: an enabling tool in nonlinear and quantum optics Adv. Opt. Photon. 2, 319–369 (2010)
- Properties of the spatial Wigner function of entangled photon pairs Phys. Rev. A 80, 043804 (2009)
- Orbital angular momentum correlations of entangled paired photons J. Opt. A: Pure Appl. Opt. 11, 094013 (2009)
- Bandwidth control of paired photons generated in monolithic Bragg reflection waveguides Opt. Lett. 34, 2000-2002 (2009)
- Space-QUEST: experiments with quantum entanglement in space Europhys. News 40, 26-29 (2009)
- Observation of two-dimensional coherent surface vector lattice solitons Opt. Lett. 34, 1624-1626 (2009)
- Tailoring the spectral coherence of heralded single photons Opt. Lett. 34, 1177-1179 (2009)
- Broadering the bandwidth of entangled photons: a step towards the generation of extremely short biphotons Phys. Rev. A 79, 023817 (2009)
- Angular dispersion in spontaneous parametric down conversion: a tool to generate narrow temporal biphotons and pure heralded single photons Int. J. Quantum Inf. 7, 9-15 (2009) Link to Int. J. Quantum Inf.
- Generating ultra-broadband biphotons via chirped QPM down-conversion Opt. Photon. News 19, 36 (2008) Optics in 2008
- Determination of the total angular momentum of a paraxial beam Phys. Rev. A 78, 053819 (2008)
- Spatiotemporal correlations in entangled photons generated by sponteneous parametric down conversion New J. Phys. 10, 113012 (2008)
- Spatial entanglement of paired photons generated in cold atomic ensembles Phys. Rev. A 78, 052301 (2008)
- Ultrabroadband biphotons generated via chirped quasi-phase-matched optical parametric down-conversion Phys. Rev. Lett. 100, 183601 (2008)
- Generation of indistinguishable and pure heralded single photons with tunable bandwidth Opt. Lett. 33, 875-877 (2008)
- Correlations in orbital angular momentum of spatially entangled paired photons generated in parametric down-conversion Phys. Rev. A 77, 015810 (2008)
- Shaping the waveform of entangled photons Phys. Rev. Lett. 99, 243601 (2007)
- Azimuthal distinguishability of entangled photons generated in spontaneous parametric down-conversion Opt. Express 15, 14636-14643 (2007)
- Tunable control of the frequency correlations of entangled photons Opt. Lett. 32, 2339-2341 (2007)
- Twisted photons
Nature Phys. 3, 305-310 (2007)
Link to Nature Phys.
Highlighted in Nature Photonics 1, 349 (2007) - Transverse entanglement migration in Hilbert space Phys. Rev. A 75, 050101(R) (2007)
- Probing canonical geometrical objects by digital spiral imaging JEOS Rapid Publications 2, 07014 (2007)
- How a Dove prism transforms the orbital angular momentum of a light beam Opt. Express 14, 9093-9102 (2006)
- Spectral engineering of entangled two-photon states Phys. Rev. A 73, 063802 (2006)
- Broadband light generation by noncollinear parametric downconversion Opt. Lett. 31, 253-255 (2006)
- Control of the shape of the spatial mode function of photons generated in noncollinear SPDC Phys. Rev. A 72, 065802 (2005)
- The spatial shape of entangled photon states generated in non-collinear, walking parametric downconversion J. Opt. B. 7, 235-239 (2005)
- Compensation of third-order dispersion in a 100 Gb/s single channel system with in-line fibre Bragg gratings J. Mod. Opt. 52, 1197-1206 (2005)
- Indistinguishability of entangled photons generated with achromatic phase matching Phys. Rev. A 71, 022320 (2005)
- Digital spiral imaging Opt. Express 13, 873-881 (2005)
- Engineering the frequency correlations of entangled two-photon states by achromatic phase matching Opt. Lett. 30, 314-316 (2005)
- Spatial-to-spectral mapping in spontaneous parametric down-conversion Phys. Rev. A 70, 043817 (2004)
- Enhancing the axial resolution of quantum optical coherence tomography by chirped quasi-phase matching Opt. Lett. 29, 2429-2431 (2004)
- Orbital angular momentum of entangled counterpropagating photons Opt. Lett. 29, 1939-1941 (2004)
- Four-wave mixing of light beams with engineered orbital angular momentum in cold cesium atoms Opt. Lett. 29, 1515-1517 (2004)
- Eigenvalue control and switching by fission of multisoliton bound states in planar waveguides Opt. Lett. 29, 483-485 (2004)
- Observation of self-trapping of light in walk-off-compensating tandems Opt. Lett. 29, 382-384 (2004)
- Quasi-phase-matching engineering for spatial control of entangled two-photon states Opt. Lett. 29, 376-378 (2004)
- Stable vortex dipoles in nonrotating Bose-Eintein condensates Phys. Rev. A 68, 063609 (2003)
- Observation of the orbital angular momentum spectrum of a light beam Opt. Lett. 28, 2285-2287 (2003)
- Quantum spiral bandwidth of entangled two-photon states Phys. Rev. A 68, 050301(R) (2003)
- Orbital angular momentum of photons in noncollinear parametric downconversion Opt. Commun. 228, 155-160 (2003)
- Deflection of quadratic solitons at edge dislocations Opt. Lett. 28, 1439-1441 (2003)
- Arresting wave collapse by wave self-rectification Phys. Rev. Lett. 91, 063904 (2003)
- Simultaneous frequency conversion and beam shaping for optical-tweezers applications J. Mod. Opt. 50, 1563-1572 (2003)
- Preparation of engineered two-photon entangled states for multidimensional quantum information Phys. Rev. A 67, 052313 (2003)
- Observation of multiple soliton generation mediated by amplification of asymmetries Phys. Rev. E 67, 046616 (2003)
- Multidimensional quantum states of the angular momentum of light Opt. Photon. News 13, 54 (2002) Optics in 2002
- Optical vortex streets Opt. Photon. News 13, 56 (2002) Optics in 2002
- Proceedings & Book Chapter
- 100 MHz amplitude and polarization modulated optical source for free-space quantum communications at 850 nm PSATA 2010, LNICST 43, 291-298 (2010)
- Quantum Cryptography Progress in Optics, vol. 49, Ed. E. Wolf (Elsevier, Amsterdam August 2006), 381-454.
- Twisted photons: new classical and quantum applications in Lasers and applications, Proc. SPIE 5958, 2005 SPIE conference, Warsaw, Poland, 28 August- 2 September 2005
- Quantum state engineering for spatial control of entangled photon pairs in Nanomanipulation with light, Proc. SPIE 5736, 173, 2005 SPIE conference, San Jose, USA, 25-26 january 2005
- The orbital angular momentum of photons in noncollinear spontaneous parametric downconversion in Nanomanipulation with light, Proc. SPIE 5736, 138, 2005 SPIE conference, San Jose, USA, 25-26 January 2005
- Articles in Magazines
- Optical metrology techniques harness structured light beams Photonics Spectra 3, 56-59 (2017)
- Happy birthday laser! Optics & Photonics Focus 9, 3 (2010)
- Make two, keep one Optics & Photonics Focus 3, 3 (2008)
- Invited Talks
- Generation of periodic structured illumination patterns with compact birefringent elements Frontiers in Optics 2019, Washington DC, USA, September 2019
- Compact entangled-pair and low-number-of-photon sources for quantum communication in space Photonics North, Montreal, Canada, June 2012
- Compact optical sources for quantum communications 4th International Symposium on Applied Sciences in Biomedical and Communication Technologies (ISABEL 2011), Barcelona, Spain, October 2011
- Quantum transceiver for secure global communications Quantum Comm, Vico Equense, Sorrento peninsula, Italy, October 2009
- Talks
- Multispectral interferometric onChip microscopy for biosensing CLEO/Europe-EQEC 2017, Munich, Germany, June 2017
- Enhancing the sensitivity of temperature sensing with Fiber Bragg Gratings with a weak value amplification scheme CLEO/Europe-EQEC 2015, Munich, Germany, June 2015
- Ultra-bright source of polarization-entangled photons in a linear double-pass configuration CLEO/Europe-EQEC 2013, Munich, Germany, May 12-16, 2013
- A high brightness source of polarization entangled photons for applications in free-space ICSOS 2012: International Conference on Space Optical Systems and Applications, Ajaccio, France, October 9-12, 2012
- Space-QUEST: experiments with quantum entanglement in space 59th International Astronautical Congress (IAC) 2008, Glasgow, United Kingdom, 29 September-3 October 2008
- Posters
- A high-brightness source of polarization-entangled photons for applications in space QCMC 2012: 11th International Conference on Quantum Communication, Measurement and Computing, Vienna, Austria, July-August 2012
- Active and passive optical sources for QKD CLEO/Europe-EQEC 2011, Munich, Germany, May 22-26, 2011
- PhD Theses
- Entanglement, Bell\'s inequalities and coherence: New ideas and new scenarios
- Entanglement, Bell’s inequalities and coherence: New ideas and new scenarios
- Weak value amplification: New insights and applications
- Photonic applications based on the use of orbital angular momentum of light
- Photonic entanglement: New sources and new applications
- Quantum-base spectroscopy and efficient energy transport with biomolecules
- Spatial characterization of two-photon states
- Spectrum shaping of paired photons
- Measurement of the spatial shape of photons
- Optimización de las prestaciones de enlaces ópticos submarinos de gran capacidad y larga distancia mediante el control de la dispersión
Quantum Engineering of Light
Prof. Dr. Juan P. Torres

- 2019-06-10 Multicolored light twists in new knotted ways ICFO researchers report on the discovery of a new type of optical singularity with the topology of a knot.
- 2017-01-23 Opto-mechanical components built with 3D printing A study published in PLOS ONE, resulting from a collaboration between Universidad de los Andes and ICFO, reports on the development of opto-mechanical components created with 3D printing.
- 2016-08-02 Summer Lecture: JUAN P. TORRES \'Entanglement: folktales, truths, dreams\'
JUAN P. TORRES
Quantum Engineering Of Light
ICFO-The Institute of Photonic Sciences - 2015-10-30 UC MEXUS Monarch Award ICFO Alumnus Roberto de León Montiel receives the UC MEXUS Monarch Award 2015
- 2014-10-17 Congratulations to New ICFO PhD graduate Dr. Jiří Svozilík graduated with a thesis in ‘Photonic Entanglement: New Sources and New Applications’
- 2014-09-30 Congratulations to New ICFO PhD graduate Dr. Roberto de J. León-Montiel graduated with a thesis in ‘Quantum-Based Spectroscopy and Efficient Energy Transport with Biomolecules’
- 2014-03-17 Hyperentanglement Generating a zoo of hyperentangled photons in semiconductor waveguides.
- 2013-05-10 Back-to-back issues of Optics Express Two ICFO papers describe novel experimental set-ups for the generation of polarization-entangled photons.
- 2012-06-15 ICFO in Nature Physics The groups led by Juan P. Torres and Antonio Acin present the first demonstration for experimentally assessing the dimension (dimension witness) of an unknown quantum system from measurement data alone.
- 2010-12-31 ICFO in Karakia Dr. Martin Hendrych presents typical Czech food at a popular TV international cooking program.
- 2010-03-12 New PhD Graduate Dr. Clara Inés Osorio obtained her PhD with a thesis on the characterization of multiple photon states.
- 2010-03-05 New PhD Graduate Dr. Xiaojuan Shi obtained her PhD with a thesis on quantum engineering of light.
- 2010-01-15 New ICFO PhD Graduate Dr. Noelia González obtained her PhD with a thesis on measurements of the spatial shape of photons.
- 2009-10-08 Nobel Prize for Working Light! ICFO congratulates laureate pioneers in light technology.
- 2009-10-06 ICFO for Senior Adults Prof. Juan P. Torres gives a talk under a UPC education extension program.
- 2009-09-30 Teaming up with ESA ICFO coordinates a project to develop an efficient entangled photon source for quantum communications in space.
- 2009-08-31 EU-Mexico Collaboration ICFO is one of the partners of a new collaboration agreement between three Mexican research institutions, three European research centers and two telecom companies.
- 2009-05-14 Chinese Government Award Ms. Xiaojuan Shi received the Chinese Government Award for Outstanding Students Abroad from China\'s Ambassador in Spain.
- 2009-05-11 Record Downloading A paper by the group led by Prof. Juan P. Torres hits a record number of downloads.
- 2009-04-28 ICFO in Canal 33 Prof. Juan P. Torres described the basics of lasers in the science program Quèquicom.
- 2009-04-27 ICFO PhD Student Awarded Chinese Government Prize Ms. Xiaojuan Shi recepient of a Chinese Government Award for Outstanding Students.
- 2008-12-12 ICFO on OPN\'s cover
A new source of entangled light, designed at ICFO, highlighted in the December issue of OPN Optics of
the Year. - 2008-05-12 ICFO in El País The development of a Quantum Transceiver is the topic of a feature in the national newspaper.
- 2008-02-08 ICFO in OPN Roser Juanola and Gabriel Molina’s research is the After Image of OPN current issue.
- 2007-12-10 ICFO in Space-Quest ICFO joins the Topical Team Space-Quest.
- 2007-05-04 Twisted photons in Nature Physics The article reviews some of the landmark advances in the study of the orbital angular momentum of photons
- 2006-12-04 QOIT Kick-off Meeting at ICFO The participants in the ‘Quantum Optical Information Technology’ project meet at ICFO and initiate their collaboration
- 2005-07-15 Green light to Quantum Information in Europe Four ICFO groups will pilot several wokpackages in two European Integrated Projects: \'Qubit Applications\' and \'Scalable quantum computing with light and atoms\'
- 2005-03-01 \'Digital Spiral Imaging\': a new concept in imaging and probing with light A new optical technique put forward by ICFO researchers published in Optics Express this February and highlighted by Physics News Update
- 2005-01-27 The Institute welcomes new members Noelia González, Marc Maymó and Albert Molinos have joined ICFO this month
- 2004-11-18 ICFO participates in a leading European research consortium in ultracold atoms and molecules (QUDEDIS) The Institute takes part in a European network aimed at the investigation of the key concepts behind the manipulation of ultracold atomic and molecular systems
- 2004-07-21 QUANTUM OPTICS WEEK From 14 to 18 of June, at ICFO