Photon Upconversion Spectroscopy
Priyam Singh, Prabhakar Singh, and S. K. Singh
Abstract This chapter discusses photon upconversion spectroscopy technique,
which is a nonlinear spectroscopy technique that converts low energy photons into
high energy photons. It is different from two photon absorption (TPA) and simple
harmonic generation (SHG) upconversion processes as it is observed through the
involvement of sequential absorption of incident photons between real stationary
states. Due to this unique feature, the non-linear upconversion emission can be
achieved at very low pump power (few mW) through continuous wave laser.
Lanthanide ions doped in different hosts (e.g. oxides, garnets, orthoniobates, fluorides, etc.) are the most suitable activators to achieve photon upconversion emission. This chapter gives a brief description of theoretical background as well as
detailed description of experimental setup for photon upconversion spectroscopy.
In the end, it also covers a few model examples to achieve photon upconversion
emission and their applications in different important areas such as for bio-imaging,
sensing, lighting and display, security, etc.
Keywords Photon upconversion · Nonlinear spectroscopy · Lanthanide ·
Bio-imaging
1 Introduction
1.1 Photon Upconversion
Optical materials continued to attract intense attention due to tremendous development in the field of lighting devices, biomedicine, optical sensors, etc. Till recently,
various optical materials including organic dyes, semiconductor QDs, plasmonic
metal nanoparticles, fluorescent proteins, organometallic complexes and lanthanidedoped inorganic phosphors, etc. have been materialized [1–6]. Sir George Gabriel
Stoke published a paper entitled “on the refrangibility (i.e. change in the wavelength
P. Singh · P. Singh · S. K. Singh (B)
Department of Physics, Indian Institute of Technology (BHU), Varanasi 221005, India
e-mail: sunilks.app@itbhu.ac.in
© The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2021
D. K. Singh et al. (eds.), Modern Techniques of Spectroscopy, Progress in Optical Science
and Photonics 13, https://doi.org/10.1007/978-981-33-6084-6_15
389
Priyam Singh, Prabhakar Singh, and S. K. Singh
Abstract This chapter discusses photon upconversion spectroscopy technique,
which is a nonlinear spectroscopy technique that converts low energy photons into
high energy photons. It is different from two photon absorption (TPA) and simple
harmonic generation (SHG) upconversion processes as it is observed through the
involvement of sequential absorption of incident photons between real stationary
states. Due to this unique feature, the non-linear upconversion emission can be
achieved at very low pump power (few mW) through continuous wave laser.
Lanthanide ions doped in different hosts (e.g. oxides, garnets, orthoniobates, fluorides, etc.) are the most suitable activators to achieve photon upconversion emission. This chapter gives a brief description of theoretical background as well as
detailed description of experimental setup for photon upconversion spectroscopy.
In the end, it also covers a few model examples to achieve photon upconversion
emission and their applications in different important areas such as for bio-imaging,
sensing, lighting and display, security, etc.
Keywords Photon upconversion · Nonlinear spectroscopy · Lanthanide ·
Bio-imaging
1 Introduction
1.1 Photon Upconversion
Optical materials continued to attract intense attention due to tremendous development in the field of lighting devices, biomedicine, optical sensors, etc. Till recently,
various optical materials including organic dyes, semiconductor QDs, plasmonic
metal nanoparticles, fluorescent proteins, organometallic complexes and lanthanidedoped inorganic phosphors, etc. have been materialized [1–6]. Sir George Gabriel
Stoke published a paper entitled “on the refrangibility (i.e. change in the wavelength
P. Singh · P. Singh · S. K. Singh (B)
Department of Physics, Indian Institute of Technology (BHU), Varanasi 221005, India
e-mail: sunilks.app@itbhu.ac.in
© The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2021
D. K. Singh et al. (eds.), Modern Techniques of Spectroscopy, Progress in Optical Science
and Photonics 13, https://doi.org/10.1007/978-981-33-6084-6_15
389