PLASMONICS, OPTOMECHANICS AND CHIRAL PHOTONICS

Alejandro Martínez

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This group studies the integration of complex nanophotonic strictures, namely plasmonic resonators and optomechanical cavities, into silicon-based photonic integrated circuits.

Plasmonic nanostructures are made of metals, and thus they allow for overcoming the diffraction limit and achieving light manipulation at subwavelength scales. Usually, they are illuminated using free-space light beams but plasmonics may also find utility for ion-chip photonics. Our final goal is improving current state-of-the-art photonic integrated circuits using plasmonic nanocavities and their extreme light localization properties.

But not only plasmonic nanostructures can improve the performance of current state-of-the-art silicon photonic chips. Recently, optomechanics has revealed itself as research hot-topic since it provides adequate mechanisms to make light and sound interact at the nanoscale. In our group, we deal with optomechanical cavities built on silicon chips to manipulate GHz vibrations optically with the final aim of getting ultra-compact microwave photonic circuitry on silicon.

Molecules can also be considered as THz mechanical oscillators and they motion can be controlled and manipulated by placing such molecules into plasmonic gaps, leading to the field know and molecular optomechanics, which aims at applications such as on-chip surface enhanced Raman scattering or ultrafast THz detection.

Finally, we also study the formation of chiral waves in photonic integrated systems with the final aim of performing chiral spectroscopy and enantiomeric separation in an on-chip platform.

The integration of plasmonic, optomechanical, and chiral elements onto silicon-photonics chips is a key step towards future nanophotonic circuits, which is a goal pursued in our group. Envisaged applications include all-optical signal processing, microwave photonics, nanospectroscopy, and chemo-bio-sensing.

Dual-mode phonon dynamics and lasing in optomechanical cavities
Raúl Ortiz, Alejandro Martínez, Carlos Mas Arabí, Carles Milián
Phys. Rev. Research 7, 043109 (2025).

Multiplexed Microphotonic Ring Resonator Platform for Simultaneous Detection of SARS-CoV-2 Spike Protein and Respiratory Syncytial Virus-F Protein
Annabella la Grasta, María Isabel Gómez-Gómez, Amadeu Griol, Estefanía Gómez, Alejandro Martínez, and Francesco Dell’Olio
IEEE Sensors J. 25(19), 36064 (2025).

E. coli filament buckling modulates Min patterning and cell division
Marta Nadal, Léna Guitou, Iago Diez, Juan Hurtado, Alejandro Martínez, Iago Grobas, Javier Buceta
Nature Comm. 16:8193 (2025).

Polarization-insensitive integration of nanoparticle-on-a-slit cavities with dielectric waveguides for on-chip surface enhanced Raman spectroscopy
J. Redolat, D. Arenas-Ortega, A. Barreda, A. Griol, E. Pinilla-Cienfuegos, and A. Martínez,
Npj Nanophoton. 2, 17 (2025).

Integrated microphotonic platform for highly sensitive virus detection
A. la Grasta, M.I. Gómez-Gómez, A. Griol, E. Gómez, M. De Carlo, V.M.N. Passaro, A. Martínez, F. Dell’Olio
Sensors and Actuators Reports 9,100320 (2025).

Bricks-on-pedestals silicon optomechanical cavity: a mass sensor for nanoparticles detection
Alberto Grau, Laura Mercadé, Raúl Ortiz, and Alejandro Martínez,
Opt. Express 33, 1458-1465 (2025)

Performance Evaluation of Dual-Drive Mach-Zehnder Modulator and Optomechanical Crystal Cavity Comb generation for All-Optical Band Conversion in 5G-Advanced Cellular Systems
V. Fito, R. Ortiz, M. Morant, L. Mercadé, A. Martínez and R. Llorente
IEEE Photonics Journal, vol. 17, no. 1, pp. 1-9 (2025).


Experimental Evaluation of All-Optical Up- and Down-Conversion of 3GPP 5G NR Signals Using an Optomechanical Crystal Cavity Frequency Comb
Vicente Fito, Raul Ortiz, Maria Morant, Laura Mercade, Roberto Llorente, Alejandro Martinez,
IEEE/OSA Journal of Lightwave Technology, 42(19), 6825-6831, 2024

Optomechanical Cavities Based on Epitaxial GaP on Nominally (001)-Oriented Si

P. Mouriño, L- Mercadé, M. S. Lozano, R. Resta, A. Griol, K. B. Saddik, E. Barrigón, S. Fernández-Garrido, B. J. García, A. Martínez, and V. J. Gómez
Advanced Materials Technologies 9, 2400525 (2024).

Integrated subwavelength bimodal interferometer using a multilayer hyperbolic metamaterial,
Luis M. Máñez-Espina and Alejandro Martínez,
Opt. Lett. 49, 6437-6440 (2024)

Cascaded injection locking of optomechanical crystal oscillators
David Alonso-Tomás, Guillermo Arregui, Laura Mercadé, Alejandro Martínez, Amadeu Griol, Néstor E. Capuj, and Daniel Navarro-Urrios,
APL Photonics 9 (11): 116108 (2024)

Longitudinal chiral forces in photonic integrated waveguides to separate particles with realistically small chirality,
Josep Martínez-Romeu, Iago Diez, Sebastian Golat, Francisco J Rodríguez-Fortuño, Alejandro Martínez,
Nanophotonics 13 (23), 4275-4289 (2024).

Bricks-on-pedestals silicon optomechanical cavity: a mass sensor for nanoparticles detection
Alberto Grau, Laura Mercadé, Raúl Ortiz, and Alejandro Martínez,
Opt. Express 33, 1458-1465 (2025)

Integrated subwavelength bimodal interferometer using a multilayer hyperbolic metamaterial,
Luis M. Máñez-Espina and Alejandro Martínez,
Opt. Lett. 49, 6437-6440 (2024)

Cascaded injection locking of optomechanical crystal oscillators
David Alonso-Tomás, Guillermo Arregui, Laura Mercadé, Alejandro Martínez, Amadeu Griol, Néstor E. Capuj, and Daniel Navarro-Urrios,
APL Photonics 9 (11): 116108 (2024)

Longitudinal chiral forces in photonic integrated waveguides to separate particles with realistically small chirality,
Josep Martínez-Romeu, Iago Diez, Sebastian Golat, Francisco J Rodríguez-Fortuño, Alejandro Martínez,
Nanophotonics 13 (23), 4275-4289 (2024).

Synthesis and Raman Detection of 5-Amino-2-mercaptobenzimidazole Self-Assembled Monolayers in Nanoparticle-on-a-Mirror Plasmonic Cavity Driven by Dielectric Waveguides.

Javier Redolat, María Camarena-Pérez, Amadeu Griol, Miguel Sinusia Lozano, Maria Isabel Gómez-Gómez, J. Enrique Vázquez-Lozano, Ermanno Miele, Jeremy J. Baumberg, Alejandro Martínez, and Elena Pinilla-Cienfuegos,
Nano Lett. 24 (12), 3670–3677, 2024.

Optical dipolar chiral sorting forces and their manifestation in evanescent waves and nanofibers.
Sebastian Golat, Jack J. Kingsley-Smith, Iago Diez, Josep Martinez-Romeu, Alejandro Martínez, and Francisco J. Rodríguez-Fortuño
Phys. Rev. Research 6, 023079, 2024).

Chiral forces in longitudinally invariant dielectric photonic waveguides.
Josep Martínez-Romeu, Iago Diez, Sebastian Golat, Francisco J. Rodríguez-Fortuño, and Alejandro Martínez
Photonics Research Vol. 12, Issue 3, pp. 431-44, 2024.

Influence of thermal effects on the optomechanical coupling rate in acousto-optic cavities.
Raúl Ortiz, Laura Mercadé, Alberto Grau, Daniel Navarro-Urrios, and Alejandro Martínez
Phys. Rev. A 109, 023504, 2024.

Unidirectional Synchronization of Silicon Optomechanical Nanobeam Oscillators by External Feedback.
David Alonso-Tomás, Néstor E. Capuj, Laura Mercadé, Amadeu Griol, Alejandro Martínez, and Daniel Navarro-Urrios
ACS Photonics 11, 1, 7–12, 2024.

1310 nm TM grating couplers to operate silicon nitride ring resonator biosensors.
Lucía Castelló-Pedrero, María I. Gómez-Gómez, David Zurita, Jaime García-Rupérez, Amadeu Griol, and Alejandro Martínez
Results in Optics 11, 100418, 2023.

Light Guidance Aided by the Toroidal Dipole and the Magnetic Quadrupole in Silicon Slotted-Disk Chains.
Evelyn Díaz-Escobar, Angela I. Barreda, Laura Mercadé, Amadeu Griol, Alessandro Pitanti, Alejandro Martínez
ACS Photonics 10, 707–714, 2023.

Plasma-induced Surface Modification of Sapphire and Its Influence on Graphene Grown by Plasma-Enhanced Chemical Vapour Deposition.

Miguel Sinusia Lozano, Ignacio Bernat-Montoya, Todora Ivanova Angelova, Alberto Boscá Mojen, Francisco J. Díaz-Fernández, Miroslavna Kovylina, Alejandro Martínez, Elena Pinilla Cienfuegos and Víctor J. Gómez
Nanomaterials 13, 1952, 2023.

Engineering multiple GHz mechanical modes in optomechanical crystal cavities
L. Mercadé, R. Ortiz, A. Grau, A. Griol, and A. Martínez
Physical Review Applied 19, 014043, 2023.

Accurate Transfer of Individual Nanoparticles onto Single Photonic Nanostructures
Javier Redolat, María Camarena-Pérez, Amadeu Griol, Miroslavna Kovylina, Angelos Xomalis, Jeremy J. Baumberg, Alejandro Martínez, and Elena Pinilla-Cienfuegos
ACS Applied Materials & Interfaces  15, 2, 3558–3565, 2023.

Experimental observation of higher-order anapoles in individual silicon disks under in-plane illumination
Evelyn Díaz-Escobar, Ángela I. Barreda, Amadeu Griol, and Alejandro Martínez
Applied Physics Letters 121, 201105, 2022.

Enhanced excitation and readout of plasmonic cavity modes in NPoM via SiN waveguides for on-chip SERS
J. E. Vázquez-Lozano, J. J. Baumberg, and A. Martínez
Optics Express, Vol. 30, pp. 4553-4563, 2022.

Room-temperature silicon platform for GHz-frequency nano-electro-opto-mechanical systems
D. Navarro-Urrios, M. F. Colombano, G. Arregui, G. Madiot, A. Pitanti, A. Griol, T. Makkonen, J. Ahopelto, C. M. Sotomayor-Torres and A. Martínez
ACS Photonics, vol. 9, pp. 413-419, 2022.

Giant injection-locking bandwidth of a self-pulsing limit-cycle in an optomechanical cavity
Daniel Navarro-Urrios, Guillermo Arregui, Martín F. Colombano, Juliana Jaramillo-Fernández, Alessandro Pitanti, Amadeu Griol, Laura Mercadé, Alejandro Martínez and Néstor E. Capuj
Communications Physics 5, 330, 2022.

Optomechanical Modulation Spectroscopy of Bound States in the Continuum in a Dielectric Metasurface
S. Zanotto, G. Conte, L. C. Bellieres, A. Griol, Daniel Navarro-Urrios, A. Tredicucci, A. Martínez, and A. Pitanti
Phys. Rev. Applied 17, 044033, 2022.

Testing Optomechanical Microwave Oscillators for SATCOM Application
Laura Mercadé , Eloy Rico , Jesús Ruiz Garnica , Juan Carlos Gómez , Amadeu Griol , Miguel A. Piqueras, Alejandro Martínez, and Vanessa C. Duarte
Journal of Lightwave Technology, vol. 40, pp. 4539-4547, 2022.

Thermal Properties of Nanocrystalline Silicon Nanobeams
J. Maire, E. Chavez-Angel, G. Arregui, M. F. Colombano, N. E. Capuj, A. Griol, A. Martínez, D. Navarro-Urrios, J. Ahopelto, C. M. Sotomayor-Torres
Advanced Functional Materials 32, 2105767, 2022.

Photonic Bandgap Closure and Metamaterial Behavior in 1D Periodic Chains of High-Index Nanobricks
Evelyn Díaz-Escobar, Laura Mercadé, Ángela I. Barreda, Jaime García-Rupérez, and Alejandro Martínez
Photonics 9(10), 691, 2022.

Hybrid photonic-plasmonic cavity design for very large Purcell factors at telecom wavelengths
Ángela Barreda, Laura Mercadé, Mario Zapata-Herrera, Javier Aizpurua, and Alejandro Martínez
Physical Review Applied 18, 044066, 2022.

Injection locking in an optomechanical coherent phonon source
G. Arregui, M. F. Colombano, J. Maire, A. Pitanti, N. E. Capuj, A. Griol, A. Martínez, C. M. Sotomayor-Torres, D. Navarro-Urrios
Nanophotonics, Vol. 10, pp. 1319–1327, 2021.

Vertical Engineering for Large Brillouin Gain in Unreleased Silicon-Based Waveguide
L. Mercadé, A. V. Korovin, Y. Pennec, J. Ahopelto, B. Djafari-Rouhani, and A. Martínez
Physical Review Applied, Vol. 15, 034021, 2021

Interfering Plasmons in Coupled Nanoresonators to Boost Light Localization and SERS
A. Xomalis, X. Zheng, A. Demetriadou, A. Martínez, R. Chikkaraddy, J. J. Baumberg
Nano Letters, Vol.  21, pp. 2512–2518, 2021.

Floquet Phonon Lasing in Multimode Optomechanical Systems
L. Mercadé, K. Pelka, R. Burgwal, A. Xuereb, A. Martínez, E. Verhagen
Physical Review Letters, Vol. 127, 073601, 2021.

Radiationless anapole states in on-chip photonics
E. Díaz-Escobar, T. Bauer , E. Pinilla-Cienfuegos, Á. I. Barreda, A. Griol, L. Kuipers, and A. Martínez
Light: Science & Applications, Vol. 10, 204, 2021.

Photonic Frequency Conversion of OFDM Microwave Signals in a Wavelength-Scale Optomechanical Cavity
L. Mercadé, M. Morant, A. Griol, R. Llorente, A. Martínez
Laser and Photonics Reviews, Vol. 15, 2100175, 2021.

Performance improvement of a silicon nitride ring resonator biosensor operated in the TM mode at 1310 nm
L. Castelló-Pedrero, M. I. Gómez-Gómez, J. García-Rupérez, A. Griol, A. Martínez
Biomedical Optics Express, Vol. 12, pp. 7244-7260, 2021.

Hybrid photonic-plasmonic cavities based on the nanoparticle-on-a-mirror configuration
Á. I. Barreda, M. Zapata-Herrera, I. M. Palstra, L. Mercadé, J. Aizpurua, A. Femius Koenderink, A. Martínez
Photonics Research 9, 2398-2419, 2021.

Continuous-Wave Frequency Upconversion with a Molecular Optomechanical Nanocavity
W. Chen, P. Roelli, H. Hu, S. Verlekar, S. P. Amirtharaj, A. I. Barreda, T. J. Kippenberg, M. Kovylina, E. Verhagen, A. Martínez, C. Galland
Science, vol. 374, pp. 1264-1267, 2021. 

Detecting mid-infrared light by molecular frequency upconversion with dual-wavelength hybrid nanoantennas
A. Xomalis, X. Zheng, R. Chikkaraddy, Z. Koczor-Benda, E. Miele, E. Rosta, G. A. E. Vandenbosch, A. Martínez, J. J. Baumberg
Science, vol. 374, pp. 1268-1271, 2021.

High-Frequency Mechanical Excitation of a Silicon Nanostring with Piezoelectric Aluminum Nitride Layers
A. Pitanti, T. Makkonen, M. F. Colombano, S. Zanotto, L. Vicarelli, M. Cecchini, A. Griol, D. Navarro-Urrios, C. Sotomayor-Torres, A. Martínez, J. Ahopelto
Physical Review Applied, Vol. 14, 014054, 2020.

Toward Chiral Sensing and Spectroscopy Enabled by All-Dielectric Integrated Photonic Waveguides
J. E. Vázquez-Lozano, A. Martínez
Laser and Photonics Reviews, Vol. 14, 1900422, 2020.

Microwave oscillator and frequency comb in a silicon optomechanical cavity with a full phononic bandgap
L. Mercadé, L. L. Martín, A. Griol, D. Navarro-Urrios, and A. Martínez
Nanophotonics, Vol. 9, 3535, 2020.

Dispersive optomechanics of supercavity modes in high-index disks
L. Mercadé, Á. Barreda, A. Martínez
Optics Letters, Vol. 45, pp. 5238-5241, 2020.

Properties of nanocrystalline silicon probed by optomechanics
D. Navarro-Urrios, M. F. Colombano, J. Maire, E. Chávez-Ángel, G. Arregui, N. E. Capuj, A. Devos, A. Griol, L. Bellieres, A. Martínez, K. Grigoras, T. Häkkinen, J. Saarilahti, T. Makkonen, C. M. Sotomayor-Torres, J. Ahopelto
Nanophotonics, Vol. 9, pp. 4819-4829, 2020.

Near-Field Unidirectional Excitation … and Beyond
J. E. Vázquez-Lozano, A. Martínez,
Optics and Photonics News, Year in Optics, p. 58, 2019.

Near-Field Directionality Beyond the Dipole Approximation: Electric Quadrupole and Higher-Order Multipole Angular Spectra
J. E. Vázquez-Lozano, A. Martínez, F. J. Rodríguez-Fortuño
Physical Review Applied, vol. 12, 024065, 2019.

SERS Detection via Individual Bowtie Nanoantennas Integrated in Si3N4 Waveguides
J. Losada, A. Raza, S. Clemmen, A. Serrano, A. Griol, R. Baets, A. Martínez
IEEE Journal of Selected Topics on Quantum Electronics, vol. 25, no. 3, 4600806, 2019.

Synchronization of Optomechanical Nanobeams by Mechanical Interaction
M. F. Colombano, G. Arregui, N. E. Capuj, A. Pitanti, J. Maire, A. Griol, B. Garrido, A. Martínez, C. M. Sotomayor-Torres, D. Navarro-Urrios
Physical Review Letters, vol. 123, 017402, 2019.

Generalizing Optical Chirality to an Arbitrary Medium
J. E. Vázquez-Lozano, A. Martínez,
Optics and Photonics News, Year in Optics 29, 2018.

Optical modulation of coherent phonon emission in optomechanical cavities
J. Maire, N. E. Capuj, M. F. Colombano, A. Griol, A. Martinez, C. M. Sotomayor-Torres, D. Navarro-Urrios
APL Photonics 3, 126102, 2018.

Metamaterial Platforms for Spintronic Modulation of Mid-Infrared Response under Very Weak Magnetic Field
G. Armelles, L. Bergamini, N. Zabala, F. García, M. L. Dotor, L. Torné, R. Alvaro, A. Griol, A. Martínez, J. Aizpurua, A. Cebollada
ACS Photonics, Vol. 5, pp. 3956–3961, 2018.

Optical Chirality in Dispersive and Lossy Media
J. E. Vázquez-Lozano, A. Martínez
Physical Review Letters, Vol. 121, 043901, 2018.

Coherent Control of a Plasmonic Nanoantenna Integrated on a Silicon Chip
A. Espinosa-Soria , E. Pinilla-Cienfuegos, F. J. Díaz-Fernández, A. Griol, J. Martí, A. Martínez
ACS Photonics, Vol. 5, pp. 2712−2717, 2018.

Nanocrystalline silicon optomechanical cavities
D. Navarro-Urrios, N. E. Capuj, J. Maire, M. Colombano, J. Jaramillo-Fernandez, E. Chavez-Angel, L. L. Martín, L. Mercade, A. Griol, A. Martínez, C. M. Sotomayor-Torres, J. Ahopelto
Optics Express, Vol. 26, pp. 9829-9839, 2018.

Classical Emergence of Intrinsic Spin-Orbit Interaction of Light at the Nanoscale
J. E. Vázquez-Lozano, A. Martínez
Physical Review A, Vol. 97, 033804, 2018.

Polarimetry enabled by nanophotonics
A. Martínez
Science, vol. 362, pp. 750-751, 2018

On-chip optimal Stokes nanopolarimetry based on spin-orbit interaction of light
A. Espinosa-Soria, F. J. Rodríguez-Fortuño, A. Griol, A. Martínez
Nano Letters, Vol. 17, pp. 3139-3144, 2017.

Nonlinear dynamics and chaos in an optomechanical beam
D. Navarro-Urrios, N. E. Capuj, M. F. Colombano, P. D. Garcia, M. Sledzinska, F. Alzina, A. Griol, A. Martínez, C. M. Sotomayor-Torres
Nature Communications, Vol. 8, 14965, 2017.

Fano resonances and electromagnetically induced transparency in silicon waveguides loaded with plasmonic nanoresonators
R. Ortuño, M. Cortijo, A. Martínez
Journal of Optics, Vol. 19, 025003, 2017.

Diffusive-light invisibility cloak for transient illumination
B. Orazbayev, M. Beruete, A. Martínez, C. García-Meca
Physical Review A, Vol. 94, 063850, 2016.

Exploiting metamaterials, plasmonics and nanoantennas concepts in silicon photonics
F. J. Rodríguez-Fortuño, A. Espinosa-Soria, A. Martínez
Topical Review in Journal of Optics, Vol. 18, 123001, 2016.

Experimental measurement of plasmonic nanostructures embedded in silicon waveguide gaps
A. Espinosa-Soria, A. Griol, A. Martínez
Optics Express, Vol. 24, pp. 9592-9601, 2016.

Transverse spin and spin-orbit coupling in silicon waveguides
A. Espinosa-Soria, A. Martínez
IEEE Photonics Technology Letters, Vol. 28, pp. 1561-1564, 2016.

Lateral forces on circularly polarizable particles near a surface
F. J. Rodríguez-Fortuño, N. Engheta, A. Martínez, A. V. Zayats
Nature Communications, Vol. 6, 879, 2015.

Alejandro Martínez – Group leader

Laura Mercadé Morales – Lecturer

Iago Diez– Postdoctoral researcher

Jose Juan Cobo Galiana – Predoctoral researcher

Raúl Ortiz Fernández – Predoctoral researcher

Alberto Grau Martínez – Predoctoral researcher

Leyre Larraya Sancho – Predoctoral researcher

Pol Molina Grifols – Predoctoral researcher

Josep Martínez Romeu – Predoctoral researcher

Daniel Arenas Ortega – Predoctoral researcher

Former members

  • Dr. Francisco José Rodríguez-Fortuño – LinkedIn / Google Scholar

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