Entangled Two Photon Absorption Cross Section on the 808 nm Region for the Common Dyes Zinc Tetraphenylporphyrin and Rhodamine B

Abstract

We report the measurement of the entangled two-photon absorption (ETPA) cross section, σ, at 808 nm on organic chromophores in solution in a low photon flux regime. We performed measurements on zinc tetraphenylporphyrin (ZnTPP) in toluene and rhodamine B (RhB) in methanol. This is, to the best of our knowledge, the first time that σ is measured for RhB. Additionally, we report a study of the dependence of σ on the molecular concentration for both molecular systems. In contrast to previous experiments, our measurements are based on detecting the pairs of photons that are transmitted by the molecular system. By using a coincidence count circuit it was possible to improve the signal-to-noise ratio. This type of work is important for the development of spectroscopic and microscopic techniques using entangled photons.

Biphoton transmission through non-unitary objects

“…This technique may potentially be useful in applications that require number state discrimination, particularly with spatial resolution. For example, it would allow simultaneous measurement of both one-and two-photon absorption distributions of an object, or alternatively their spectra [26,27]. In this case, the two-photon portion of the transmitted state is attenuated by both one-and two-photon absorption, but single-photons are only generated by onephoton absorption.…”

Towards Heralded Two-Photon Absorption and Two-Photon Excited Fluorescence for Quantum Microscopy and Spectroscopy

“…Enhanced TPA was experimentally achieved with "classical" light by utilizing thermal light instead of coherent light [14,15]. The utilization of entangled photons for TPA was proposed by Gea-Banacloche [16] as well as Javaninen and Gould [17] and later experimentally demonstrated with atoms [18] as well as molecules [19,20,21,22]. Other nonlinear interactions utilizing entangled photons include for example sum frequency generation (SFG) [23].…”

Perspectives for Applications of Quantum Imaging

“…Hence, the penetration depth into tissue is reduced by a factor of . Nevertheless, since the initial proposal several experiments in this direction had been carried out successfully . Yet, all of them suffer from the rather low pair generation rate in the BBO crystals used for photon‐pair generation.…”

“…Nevertheless, since the initial proposal several experiments in this direction had been carried out successfully. [124][125][126][127][128] Yet, all of them suffer from the rather low pair generation rate in the BBO crystals used for photon-pair generation. However, photon pair sources based on SPDC in periodically poled crystals (e.g., ppKTP) not only allow a broader variety in wavelength selection but also tremendously enhance the photon pair rate to 1 × 10 6 counts per mW pump power, [59,129] which can be further increased by at least an order of magnitude by employing waveguide structures within the periodically poled non-linear crystals.…”