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Cited by 8Terahertz technology and applicationsSpectroscopy and Laser ApplicationsLaser-Matter Interactions and Applications

Dual-Beam THz Spectrometer with Low-Aberration Optics and Off-Axis Multipixel Photoconductive Emitters for Reduced Systematic Errors

Open access
Chopra, Nishtha, Lloyd-Hughes, James·2025·ACS Photonics
DOI 10.1021/acsphotonics.4c01934PMC PMC11843712
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Abstract

A dual-beam THz spectrometer is reported that substantially reduces the influence of systematic errors in THz time-domain spectroscopy such as those caused by variations in femtosecond laser power or the environmental temperature and humidity. Dual THz beams with single-cycle waveforms were generated simultaneously using a dual-pixel interdigitated photoconductive antenna, allowing the simultaneous acquisition of sample and reference data in the spectrometer using the same optical components. A low-aberration optical geometry ensured diffraction-limited spatial profiles for both beams despite their off-axis propagation and was validated experimentally by measuring frequency-dependent beam profiles and theoretically via physical optics calculations. Although the experimental amplitudes and absolute phase spectra of both beams were very similar, we further provided a correction procedure to eliminate these small differences. The robustness of the dual-beam spectrometer design was evaluated by measuring the complex transmission of a thin plastic sheet after intentionally introducing a change in the relative humidity of the THz beam path. The dual-beam THz spectrometer was effective at removing systematic errors in the amplitude and phase by simultaneously measuring the two THz beams under the same conditions.

AI snapshot

Written from the paper’s full text.

TL;DR

A dual-beam THz time-domain spectrometer is demonstrated using a dual-pixel photoconductive emitter and low-aberration off-axis parabolic mirror optics to acquire sample and reference beams simultaneously through the same optical path. It suppresses systematic errors from laser-power, temperature, or humidity drift, as shown by correcting single-beam artifacts caused by a controlled humidity change.

Key findings

  • The dual-pixel emitter had pixel centers spaced by Δx = 3 mm, each with a 500 × 500 μm active area, positioned at x = ±1.5 mm from the optical axis; the measured focused beams were separated by Δx = 2.8 mm, close to the 3 mm design.
  • The low-aberration (a,a)(a,a) OAPM geometry produced similar diffraction-limited profiles for both beams: at 0.3 THz, Gaussian fits gave σ1 = 0.60 mm and σ2 = 0.64 mm; at 3.0 THz, σ1 = σ2 = 0.15 mm. Spectral coverage reached 100 GHz to 6.5 THz, and |R(ω)| = |E2/E1| was within 10% of unity up to 5.5 THz.
  • With a 23 μm Mylar sheet and an intentional humidity change to 6% RH, single-beam transmission showed erroneous minima near water-vapor absorption lines (1.7, 2.2, 2.7 THz, etc.) and the relative THz amplitude dropped to around 50% at 3.0 THz for the 610 mm path length. The dual-beam transmission TdualH matched the purged “true” transmission in modulus and phase.
  • A correction procedure was provided to eliminate small amplitude and phase differences between the two beams, and the dual-beam formula removes systematic errors when both beams experience the same perturbation.

Methods

  • Experimental setup: a Ti:sapphire oscillator (100 fs, 80 MHz, 800 nm) was split into pump and probe; a transmissive DOE and 100 mm focal-length plano-convex lens produced two pump beams mainly in m = ±1 orders, giving 300 mW per beam and 3 mm spacing at the emitters. Backward-emitted THz radiation was collected, reflected by an FTO mirror, and guided by two pairs of 76.2 mm focal-length, 50.8 mm diameter OAPMs in an (a,a)(a,a) configuration. Detection used a 200 μm GaP crystal, Wollaston prism, balanced photodiodes, and lock-in amplifiers; emitters were modulated at 100 kHz with Vpp = 20 V, with emitter 2 phase-shifted by 90°.
  • Design validation used Ansys Zemax physical optics with Fresnel propagation, starting from Gaussian beams with waists w0 = 0.4 mm centered at x = ±1.5 mm. Experiments used knife-edge scans in 50 μm steps, frequency-resolved beam profiles, and a phase- and amplitude-accurate discrete Fourier transform routine.
  • Spectroscopy test: a 23 μm polyethylene terephthalate (Mylar) sheet was measured with a frequency-independent complex refractive index ñ = 1.78 + 0.03i, first under dry nitrogen purge (RH = 0%) and then after changing the THz beam path to RH = 6%.

Limitations

  • Stated: the work is a proof-of-concept free-space THz transmission setup based around a Ti:sapphire laser, though the authors state the approach can be extended to fiber-coupled systems or reflection geometry. The authors also note a small spatial overlap of the two beams at lower frequencies, which was circumvented experimentally by a modulation scheme.
  • Stated: sample positioning along z requires care because the Rayleigh range is zR = 0.77 mm at 0.3 THz and zR = 1.4 mm at 3 THz. Water-vapor line widths were limited by the 20 ps scan window.
  • Evident from the text: the robustness demonstration uses one thin plastic sample and a controlled humidity perturbation, so broader material, frequency, and environmental validation is not shown.

Model-written summary. Check it against the paper before relying on it.

Integrity signals

Registry

Crossref · 10.1021/acsphotonics.4c01934

Cites

22 of 22 references verified0 citation errors · 0 not checkable

Statistics

Nothing to recompute.

Claims the paper makes

0 of 20 cited sources checked · 0 supported · 0 flagged

  • Findingown data

    The dual-beam THz spectrometer was effective at removing systematic errors in the amplitude and phase by simultaneously measuring the two THz beams under the same conditions.

    “The dual-beam THz spectrometer was effective at removing systematic errors in the amplitude and phase by simultaneously measuring the two THz beams under the same conditions.”
    Quote in the paperSubstantial claim
  • Findingown data

    The experimental amplitudes and absolute phase spectra of both beams were very similar.

    “the experimental amplitudes and absolute phase spectra of both beams were very similar”
    Quote in the paperNot a substantial claim
  • Findingown data

    A low-aberration optical geometry ensured diffraction-limited spatial profiles for both beams despite their off-axis propagation.

    “A low-aberration optical geometry ensured diffraction-limited spatial profiles for both beams despite their off-axis propagation”
    Quote in the paperSubstantial claim
  • Findingreasoning

    The imaging system guides the two beams in free space, ensuring a diffraction-limited spot size at both the sample and detector planes.

    “These mirrors guide the two beams in free space, ensuring a diffraction-limited spot size at both the sample and the detector planes.”
    Quote in the paperSubstantial claim
  • Findingown data

    With the plastic sample in beam 2, |Tsingle,2| reduces in amplitude to 0.86 at 2 THz before increasing.

    “With the plastic sample placed in beam 2, |Tsingle,2| (orange line) can be seen to reduce in amplitude to 0.86 at 2 THz, before increasing.”
    Quote in the paperNot a substantial claim
  • May combine two claims. 33
  • Classified as probably not a substantial claim. 5

  • May combine two claims.

    Findingown data

    Dual THz beams with single-cycle waveforms were generated simultaneously using a dual-pixel interdigitated photoconductive antenna, allowing simultaneous acquisition of sample and reference data in the spectrometer using the same optical components.

    “Dual THz beams with single-cycle waveforms were generated simultaneously using a dual-pixel interdigitated photoconductive antenna, allowing the simultaneous acquisition of sample and reference data in the spectrometer using the same optical components.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    The two beams had similar frequency-dependent sizes, with σ1 ≃ σ2.

    “The similarity between the profiles can be further seen in Figure 3d, where it is evident that σ1 ≃ σ2, and both beams had similar frequency-dependent sizes.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    Single-cycle THz pulses were obtained for both beams, with beam 1 arriving 2.3 ps later than beam 2 due to differing optical path lengths of probe beams 1 and 2.

    “Single-cycle THz pulses were obtained for both THz beams 1 and 2, with pulses in beam 1 arriving 2.3 ps later than beam 2, as a result of the differing optical path lengths of probe beams 1 and 2.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    The two beams were tightly focused in the sample focal plane (z = 0) and were separated by a distance Δx = 2.8 mm, close to the device's designed separation of 3 mm.

    “As shown in Figure 3a, the two beams were tightly focused in the sample focal plane (z = 0) and were separated by a distance Δx = 2.8 mm, close to the device’s designed separation of 3 mm.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    At all frequencies, the two beams are circular, and beam cross sections are close to Gaussian in shape.

    “At all frequencies, the two beams are circular, and beam cross sections are close to Gaussian in shape”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    At f = 0.3 THz, the two beams had similar amplitude profiles, consistent with Gaussian beams with σ1 = 0.60 mm and σ2 = 0.64 mm.

    “As reported in Figure 3b, the beams had similar amplitude profiles at f = 0.3 THz (points), which were consistent with error function fits (black lines) corresponding to Gaussian beams with σ1 = 0.60 mm and σ2 = 0.64 mm (shaded areas).”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    The two THz beams had similar spatial profiles but were well-separated by the design distance in an intermediate focal plane.

    “we first demonstrate that the two THz beams had similar spatial profiles but were well-separated by the design distance in an intermediate focal plane.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    The traditional single-beam approach was very sensitive to variations in atmospheric humidity levels, while the dual-beam method reliably reproduced the correct complex transmission.

    “While the traditional single-beam approach was very sensitive to variations in atmospheric humidity levels, our dual-beam method reliably reproduced the correct complex transmission.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    Amplitude spectra show good spectral coverage from 100 GHz to 6.5 THz, with very similar spectral amplitudes for both beams (|E1| ≃ |E2|).

    “Amplitude spectra in Figure 4b show good spectral coverage from 100 GHz to 6.5 THz, with very similar spectral amplitudes for both beams, |E1(ω)| ≃ |E2(ω)|.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    The amplitude ratio |R(ω)| is within 10% of 1 over the range to 5.5 THz, with a small phase difference.

    “The amplitude |R(ω)| is within 10% of the ideal value |R| = 1 over the range to 5.5 THz, with a small phase difference ∠R(ω), as shown in Figure 4f.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    The intensity does not completely drop to zero between the beams on the optical axis for 0.3 THz, suggesting that at lower frequencies there may be some spatial overlap of the two beams.

    “The intensity does not completely drop to zero between the beams on the optical axis (x = 0, y = 0) for 0.3 THz, suggesting that at lower frequencies, there may be some spatial overlap of the two beams.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    At higher frequencies (1 THz and 3 THz), the two beams are more clearly distinct, with a higher peak intensity and smaller spot size.

    “At higher frequencies (1 THz and 3 THz frequencies), the two beams are more clearly distinct, with a higher peak intensity and smaller spot size”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    The beam profiles were sharper at higher frequencies; at f = 3.0 THz, σ1 = σ2 = 0.15 mm.

    “The beam profiles were sharper at higher frequencies, for instance, with σ1 = σ2 = 0.15 mm at f = 3.0 THz, evident in Figure 3c.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingreasoning

    At 0.3 THz with σ = 0.64 mm, the Rayleigh range is zR = 0.77 mm; at 3 THz with σ = 0.15 mm, zR = 1.4 mm.

    “For example, using σ = 0.64 mm at 0.3 THz (Figure 3d), the Rayleigh range is zR = 0.77 mm, or at 3 THz with σ = 0.15 mm, it increased to zR = 1.4 mm.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    Altering the humidity level of the spectrometer intentionally introduced systematic errors in amplitude and phase, both of which produce significant systematic errors in conventional single-beam systems.

    “To evaluate the performance of our spectrometer, we intentionally introduced systematic errors in the amplitude and phase by altering the humidity level of the spectrometer, both of which produce significant systematic errors in conventional single-beam systems.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    The low-aberration OAPM geometry achieved a diffraction-limited spot size, allowing independent sample and reference beams in the intermediate focal plane even with relatively small beam separations (3 mm here).

    “Crucially, the low-aberration (a,a)(a,a) OAPM geometry achieved a diffraction-limited spot size, allowing independent sample and reference beams in the intermediate focal plane even with relatively small beam separations (3 mm here).”
    Quote in the paperSubstantial claim

  • Classified as probably not a substantial claim. May combine two claims.

    Premisecitation

    Random noise controls the precision of results, while systematic errors influence the accuracy of material properties derived from the experiment.

    “Errors directly impact the efficacy of the parameter extraction process:3 random noise controls the precision of results, while systematic errors influence the accuracy of material properties derived from the experiment.”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [3] source

      Not checked in the free run.

  • May combine two claims.

    Study design and conductown data

    The low-aberration optical geometry was validated experimentally by measuring frequency-dependent beam profiles and theoretically via physical optics calculations.

    “was validated experimentally by measuring frequency-dependent beam profiles and theoretically via physical optics calculations.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationnone given

    Using two THz beams propagating along the same optical path mitigates against long-term drifts that cause systematic errors while reducing system complexity and cost.

    “By using two THz beams propagating along the same optical path, this approach mitigates against long-term drifts that cause systematic errors while reducing the system complexity and cost.”
    Quote in the paperSubstantial claim
    • Rests on an assumption: Fewer studies have tackled systematic errors in THz-TDS than random noise.
    • Rests on an assumption: Dual-beam spectroscopy has not been widely adopted or explored in the THz range by academic and industrial users.

  • May combine two claims.

    Interpretationown data

    The spatial, temporal, and spectral properties of the two THz beams are very similar, and above 300 GHz the two beams are spatially separated.

    “The results above show that the spatial, temporal, and spectral properties of the two THz beams are very similar and that at higher frequencies (above 300 GHz), the two beams are spatially separated.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Premisecitation

    The generalized THz ellipsometry system had roughly double the components compared to a standard THz time-domain spectrometer, adding to the system's cost and complexity.

    “While an important step forward, compared to a standard THz time-domain spectrometer, the system had roughly double the components,10 adding to the system’s cost and complexity.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [10] source

      Not checked in the free run.

  • May combine two claims.

    Interpretationreasoning

    If η = 1, the experimental transmission matches the actual transmission; if η ≠ 1, a systematic error has occurred.

    “If η = 1, then the experimental transmission matches the actual transmission function of the sample, Tsingle = T, while η ≠ 1 implies that a systematic error has occurred in the time between measurements.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Premisecitation

    Generalized THz ellipsometry used two photoconductive antennas to generate two orthogonally polarized THz beams, which were combined, reflected, split into orthogonal polarizations, and detected by two photoconductive detectors.

    “In generalized THz ellipsometry,10 two photoconductive antennas were used to generate two orthogonally polarized THz beams, which were then combined with a THz polarizer, reflected from a sample, split into orthogonal polarizations, and detected by two photoconductive detectors.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [10] source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    A standard silicon lens with the dual emitters was avoided because spherical lenses only work well for on-axis point sources.

    “The use of a standard silicon lens with the dual emitters was avoided, as spherical lenses only work well for on-axis point sources.19”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [19] source

      Not checked in the free run.

  • May combine two claims.

    Interpretationcitation

    The second pair of OAPMs propagates the two THz beams from the sample plane to the detector plane, where diffraction-limited foci with similar optical performance are expected, including some overlap of the two beams at lower frequencies.

    “The second pair of OAPMs propagates the two THz beams from the sample plane to the detector plane (Figure 1), where diffraction-limited foci with similar optical performance are expected,17 including some overlap of the two beams at lower frequencies.”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [17] source

      Not checked in the free run.

  • May combine two claims.

    Interpretationcitation

    At low frequencies, the near constant −π/2 phase is as expected for a single-cycle pulse; the nonlinear increase in phase with frequency can be assigned to chirp processes such as dispersion in the electro-optic crystal and the GaAs emitter.

    “At low frequencies, the near constant −π/2 phase is as expected for a single-cycle pulse,20 while the nonlinear increase in phase with frequency can be assigned to processes that introduce chirp, such as dispersion in the electro-optic crystal21 and the GaAs emitter.18”
    Quote in the paperNot a substantial claim0 of 3 sources checked
    • cites [20] Lloyd-Hughes J., 2024, arXiv

      Not checked in the free run.

    • cites [21] source

      Not checked in the free run.

    • cites [18] source

      Not checked in the free run.

  • Classified as probably not a substantial claim. May combine two claims.

    Interpretationnone given

    A dual-beam transmission formula for spectroscopy allows systematic errors to be removed and corrects for any amplitude and phase differences between the two beams.

    “We then define a dual-beam transmission formula for spectroscopy that allows systematic errors to be removed and which corrects for any amplitude and phase differences between the two beams.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationreasoning

    The frequency dependence of the spot size is such that σn is frequency-independent at higher frequencies (σn ≃ 0.15 mm for f ≥ 1.5 THz) and σn ∝ 1/f at longer wavelengths (f < 1 THz), where the THz beam starts to overfill the first OAPM.

    “σ is frequency-independent at higher frequencies, with σn(f) ≃ 0.15 mm for f ≥ 1.5 THz, while σn ∝ λ ∝ 1/f at longer wavelengths (f < 1 THz) where the THz beam starts to overfill the first OAPM.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Premisecitation

    Self-referencing methods rely on accurate knowledge of the substrate and make assumptions about sample geometry such as the absence of air gaps, which can introduce systematic errors during data postprocessing.

    “However, such methods rely on accurate knowledge of the substrate and make assumptions about sample geometry such as the absence of air gaps, which can introduce systematic errors during data postprocessing.”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [8] source

      Not checked in the free run.

  • May combine two claims.

    Interpretationown data

    The low-aberration design allowed good spatial separation of the two beams for frequencies of 0.3 THz and higher, enabling dual-beam spectroscopy with a sample in one beam.

    “The low-aberration design of the spectrometer allowed good spatial separation of the two beams for frequencies of 0.3 THz and higher, allowing dual-beam spectroscopy measurements to be performed by placing a sample in one of the two beams.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Premisecitation

    Double-modulation terahertz spectroscopy rapidly translates the sample into and out of the THz beam, resulting in a differential signal sensitive to subtle variations in absorption and phase.

    “Double-modulation terahertz spectroscopy achieves this by rapidly translating the sample into and out of the THz beam,6,7 resulting in a differential signal sensitive to subtle variations in absorption and phase.”
    Quote in the paperSubstantial claim0 of 2 sources checked
    • cites [6] source

      Not checked in the free run.

    • cites [7] source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Study design and conductown data

    To prohibit cross-talk in the detection plane, the two beams can be modulated at different frequencies or with orthogonal phases, such that no cross-talk is observed between the beams.

    “To prohibit cross-talk in the detection plane in the experiment (e.g., probe beam 2 sampling the edge of THz beam 1), the two beams can be modulated at different frequencies or with orthogonal phases, such that no cross-talk is observed between the beams (Supporting Information).”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Study design and conductnone given

    The line widths were limited by the 20 ps scan window of the experiment.

    “Here, the line widths were limited by the 20 ps scan window of the experiment.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Interpretationreasoning

    The dual-beam spectrometer suppressed these systematic errors by simultaneously measuring two THz beams that propagated along the same optical path, significantly enhancing accuracy and reliability.

    “Our dual-beam spectrometer was able to suppress these systematic errors by simultaneously measuring two THz beams that propagated along the same optical path, significantly enhancing the accuracy and reliability of the measurement data.”
    Quote in the paperSubstantial claim
34 of 34

  • The paper relies on this without support.

    Fewer studies have tackled systematic errors in THz-TDS than random noise.

    “However, fewer studies have tackled the systematic errors in THz-TDS.”

  • The paper relies on this without support.

    Dual-beam spectroscopy has not been widely adopted or explored in the THz range by academic and industrial users.

    “Dual-beam spectroscopy has not been widely adopted or explored in the THz range by the academic and industrial users of THz methods”

  • The authors state this as an assumption.

    The systematic error alters both THz beams in the same way (η2(ω) = η1(ω)).

    “where the last step was made assuming that η2(ω) = η1(ω).”

  • The authors state this as an assumption.

    The sample's complex refractive index is frequency-independent with ñ = 1.78 + 0.03i.

    “assuming a frequency-independent complex refractive index ñ = 1.78 + 0.03i”
4 of 4

Claims other papers make about this one

Each is checked against this paper’s own text: does it say what the citing paper says it does?

  • The mean arrival time method can be calculated automatically and rapidly via numerical integration and is accurate for pulses that are not too complex, but it cannot be used for more complex waveforms such as a pulse train created by internal reflections, because the integral is pulled later in time by pulse echoes.

    “The mean arrival time can be calculated automatically and rapidly via numerical integration and is accurate for pulses that are not too complex. For example, it can be used to correct for arrival time differences between two THz pulses in dual-beam THz spectroscopy [26]. However, it cannot be used for more complex waveforms: for instance, if the data set comprises a pulse train created by internal”

    From A Tutorial on THz Pulse Analysis: Accurate Retrieval of Pulse Arrival Times, Spectral Energy Density and Absolute Spectral Phase (2025) · cites this paper as [26]

    Split into 2 atoms — 1 confirmed, 1 partially supported, 0 disputed, 0 misattributed, 0 unverifiable. Expand the claim to see per-atom verdicts.

    Experimental — accuracy not yet measured

  • The accurate determination of the pulse arrival time may prove useful in THz time-of-flight, layer thickness, or tomography applications, and further helps to correct arrival time differences in dual-beam THz spectroscopy.

    “The accurate determination of the pulse arrival time may prove useful in THz time-offlight, layer thickness, or tomography applications [38], and further helps to correct arrival time differences in dual-beam THz spectroscopy [26].”

    From A Tutorial on THz Pulse Analysis: Accurate Retrieval of Pulse Arrival Times, Spectral Energy Density and Absolute Spectral Phase (2025) · cites this paper as [26]

Self-check

Percentages, sums and reported differences re-computed from the paper’s own numbers.

Each contradiction between two passages listed here was confirmed by an independent check.

  • Rayleigh range at 0.3 THz conflicts with the stated formula

    Minor

    At 0.3 THz, the wavelength is approximately 1 mm. Applying the paper's formula with σ = 0.64 mm gives a Rayleigh range of about 2.57 mm, not 0.77 mm; the reported 3 THz example is consistent with the formula.

1 of 1

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Related

Authors
Chopra, N., & Lloyd-Hughes, J.
Affiliations
  • University of Warwick (GB)
  • Department of Physics
Corresponding author
Chopra, Nishtha
ORCID
Venue
ACS Photonics
Publisher
American Chemical Society (ACS)
Published
2025-01-11
Volume
12
Issue
2
Pages
917-924
ISSN
2330-4022 (ISSN-L)
DOI
10.1021/acsphotonics.4c01934
PMC
PMC11843712
OpenAlex
W4406275765
Cited by
8
References
22
Citations by year
2026: 2 · 2025: 6
FWCI
1.77
Type
journal article
Language
en
Open access
Licence
Locations
  • ACS Photonics (publishedVersion, cc-by)
  • PubMed Central (publishedVersion, cc-by)
  • PubMed (publishedVersion)
  • Warwick Research Archive Portal (University of Warwick) (acceptedVersion)
Funders
Engineering and Physical Sciences Research Council (EP/V047914/1)
Topics
  • Physical Sciences › Engineering › Electrical and Electronic Engineering › Terahertz technology and applications
  • Physical Sciences › Chemistry › Spectroscopy › Spectroscopy and Laser Applications
  • Physical Sciences › Physics and Astronomy › Atomic and Molecular Physics, and Optics › Laser-Matter Interactions and Applications
Keywords
terahertz time-domain spectroscopy, systematic error reduction, photoconductive antenna, amplitude and phase correction, relative humidity effects, reference beam

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