More Like this

1. Intense THz Generation with New Organic NLO Crystal NMBA

   https://doi.org/10.1002/adom.202302402  

   Ludlow, Daisy JH; Palmer, Bruce_Wayne H; Green, Natalie K; Ho, Sin‐Hang Enoch; Wayment, Coriantumr Z; Kelleher, Brenan M; Barlow, Connor D; Rollans, Olivia N; Hunter, Brittan P; Rader, Claire; et al (January 2024, Advanced Optical Materials)

   Abstract Large crystal growth and characterization of the optical and terahertz (THz) properties of organic nonlinear optical (NLO) crystal NMBA (4‐Nitro‐4′‐methylbenzylidene aniline) is presented. The reported method of crystal growth consistently produces high‐quality single crystals. The THz generation efficiency and optical properties of NMBA to other THz generation crystals including BNA and MNA are compared. The low THz absorptions that make NMBA an ideal source for THz time‐domain spectroscopy are highlighted. 

   more » « less
2. Optical Rectification from Next Generation Organic THz Generation Crystals

   https://doi.org/10.1364/FIO.2022.JW5B.22  

   Green, Natalie K.; Palmer, Bruce Wayne; Rader, Claire; Ho,; Zaccardi, Zac; Ludlow, Daisy J.; Lutz, Matthew J.; Alejandro, Aldair; Nielson, Megan F.; Valdivia-Berroeta, Gabriel A.; et al (January 2022, Frontiers in Optics + Laser Science 2022)

   We recently developed new organic nonlinear optical crystals for THz generation. We report the optical and THz properties of PNPA and MNA and discuss how they pave the way for the future of THz spectroscopy. 

   more » « less
3. Efficient Broadband THz Generation from New Standards in Optical Rectification

   https://doi.org/10.1364/CLEO_AT.2023.JTh2A.115  

   Green, Natalie K.; Palmer, Bruce Wayne; Rader, Claire; Ho, Sin-Hang Enoch; Zaccardi, Zachary B.; Ludlow, Daisy J.; Lutz, Matthew J.; Alejandro, Aldair; Nielson, Megan F.; Valdivia-Berroeta, Gabriel A.; et al (January 2023, CLEO 2023)

   We present the optical and THz properties of highly efficient organic nonlinear optical crystals PNPA and MNA. These crystals outperform industry standards in broadband THz generation through optical rectification of IR light pulses. 

   more » « less
4. Observation of colossal terahertz magnetoresistance and magnetocapacitance in a perovskite manganite

   https://doi.org/10.1364/OPTICA.491626  

   Tay, Fuyang; Chaudhary, Swati; He, Jiaming; Marquez_Peraca, Nicolas; Baydin, Andrey; Fiete, Gregory_A; Zhou, Jianshi; Kono, Junichiro (July 2023, Optica)

   Terahertz (THz) magnetoresistance effects have been extensively investigated and have shown promising results for applications in magnetic modulations of the amplitude of THz waves. However, THz magnetocapacitance in dielectric systems, which is essential for phase modulations of THz radiation, remains largely unexplored. Here, we study the THz response of a bulk single crystal of La_0.875Sr_0.125MnO₃at around its Curie temperature, observing significant magnetic-field-induced changes in the THz resistance and capacitance extracted from the optical conductivity. We discuss possible mechanisms for the observed coexistence of colossal THz magnetoresistance and magnetocapacitance in a perovskite manganite that is not multiferroic. This work enhances our understanding of colossal magnetoresistance in a complex system with THz spectroscopy and demonstrates potential use of perovskite manganites in THz technology. 

   more » « less
5. Room temperature terahertz semiconductor frequency comb

   https://doi.org/10.1038/s41467-019-10395-7  

   Lu, Quanyong; Wang, Feihu; Wu, Donghai; Slivken, Steven; Razeghi, Manijeh (June 2019, Nature Communications)

   Abstract A terahertz (THz) frequency comb capable of high-resolution measurement will significantly advance THz technology application in spectroscopy, metrology and sensing. The recently developed cryogenic-cooled THz quantum cascade laser (QCL) comb has exhibited great potentials with high power and broadband spectrum. Here, we report a room temperature THz harmonic frequency comb in 2.2 to 3.3 THz based on difference-frequency generation from a mid-IR QCL. The THz comb is intracavity generated via down-converting a mid-IR comb with an integrated mid-IR single mode based on distributed-feedback grating without using external optical elements. The grating Bragg wavelength is largely detuned from the gain peak to suppress the grating dispersion and support the comb operation in the high gain spectral range. Multiheterodyne spectroscopy with multiple equally spaced lines by beating it with a reference Fabry-Pérot comb confirms the THz comb operation. This type of THz comb will find applications to room temperature chip-based THz spectroscopy. 

   more » « less