Abstract Yellow organic crystals, like BNA, MNA, and NMBA, can be used to generate terahertz (THz) pulses of light through optical rectification of infrared ultrafast laser pulses. When producing THz with these organic crystals, one needs to consider that 1) their damage thresholds are low due to having low melting points and 2) Fresnel reflection losses due to multiple interfaces reduce the efficiency of the generated THz output. In this work, new heterogeneous multi‐layer “sandwich” structures are developed with these yellow organic crystals by 1) fusing them to sapphire plates to permit the crystal to withstand higher laser fluences and 2) using an index‐matching fluid (liquid crystal MBBA) to decrease Fresnel reflection losses and improve the THz output. It is shown that the sapphire plates increase the damage threshold of these yellow organic crystals by a factor of two or more, thus allowing the crystals to generate higher THz electric fields. Furthermore, it is shown that the THz light output efficiency increases by assembling the yellow crystals into multi‐layered sandwich structures. For some yellow organic crystals, the sandwich structures increase the THz intensity by more than a factor of two.
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Custom terahertz waveforms using complementary organic nonlinear optical crystals
Organic nonlinear optical (NLO) crystals are among the most efficient (>1%) terahertz (THz) radiation generators. However, one of the limitations of using organic NLO crystals is that the unique THz absorptions in each crystal make it difficult to obtain a strong, smooth, and broad emission spectrum. In this work, we combine THz pulses from two complementary crystals, DAST and PNPA, to effectively fill in spectral gaps, creating a smooth spectrum with frequencies out to 5 THz. The combination of pulses also increases the peak-to-peak field strength from 1 MV/cm to 1.9 MV/cm.
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- Award ID(s):
- 2104317
- PAR ID:
- 10379835
- Publisher / Repository:
- Optical Society of America
- Date Published:
- Journal Name:
- Optics Letters
- Volume:
- 47
- Issue:
- 22
- ISSN:
- 0146-9592; OPLEDP
- Format(s):
- Medium: X Size: Article No. 5985
- Size(s):
- Article No. 5985
- Sponsoring Org:
- National Science Foundation
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