Ultrahigh-resolution rapid-scan ultraviolet-visible spectrometer

Qinghua Yang

doi:10.1364/OSAC.1.000812

1. Introduction

Since Isaac Newton first defined the “spectrum” in 1704 by separating sunlight into its constituent colors with a prism, spectroscopy has been developed significantly. Spectroscopy was first applied to astronomy in 1817 by Joseph Fraunhofer to study the solar atmosphere components. Today it is an important and efficient way to study the stars and trace the origin of the universe. It is currently much used for various kinds of scientific research and industrial applications. Based on different detection schemes, spectrometers are divided into four categories. The first category is color filter spectrometer that uses either a set of band-pass filters, a circular-variable filter, a liquid-crystal tunable filter or an acousto-optical tunable filter to get spectral information [1,2]. The second category is dispersive spectrometer that is based on either a prism, a grating or both to achieve the dispersion of light [3–9]. The third category is interferometric spectrometer (i.e., Fourier transform spectrometer) that is based on temporal interferometry or spatial interferometry [10–16]. The fourth category is coherent-dispersion spectrometer that combines interferometric and dispersive spectroscopy to obtain spectral information [17,18].

In the infrared spectral region, the detector noise exceeds all other noise sources and is independent of the incident radiation power, so the throughput and multiplex are the two advantages of interferometric over dispersive spectroscopy. In the ultraviolet-visible spectral region, the photon noise is the limiting factor and the noise level is proportional to the square root of the incident power, so the performance of the interferometric spectroscopy is weakened to measure a broadband source in the ultraviolet and visible regions [19]. One of the greatest disadvantages of existing ultraviolet-visible multiplexed spectroscopy for a broadband source is the multiplex disadvantage [14,19–23]. Except for filtering the light before detection [24,25], the coherent-dispersion spectrometer proposed in [17] is a very effective method to solve the multiplex disadvantage, but unfortunately it cannot obtain very high spectral resolution.

The temporal interferometry based on linear scanning is the very successful design to obtain ultrahigh spectral resolution for a broadband spectral range. The biggest problem associated with the use of a Michelson interferometer as a Fourier-transform spectrometer is the tilt of the moving plane mirror during scanning, which has been successfully solved by using the cat’s-eye system or corner-cube-mirror system. However, as a moving element, the volume and weight make the corner-cube-mirror or cat’s-eye retroreflector unsuitable for rapid scan.

The grating can give higher and more linear dispersion of the wavelength than the prism. Today the high quality transmission gratings can rival reflection gratings in all aspects, therefore, the transmission gratings can be used as dispersive devices in the infrared, visible, or near-ultraviolet regions [26–28].

2. Principle

This paper presents an ultrahigh-resolution rapid-scan ultraviolet-visible spectrometer (UVS), which combines a moving double-sided-mirror interferometer with a plane transmission grating. Figure 1

Fig. 1 Optical layout of the ultraviolet-visible spectrometer (UVS).

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shows the optical layout of the UVS. The moving double-sided-mirror interferometer is comprised of one moving double-sided mirror (DSM), one fixed plane mirror, one fixed corner-cube mirror, and one beam splitter. The DSM is a plane-parallel glass plate with both faces coated with high-reflectivity films. The DSM enables the two beams reflecting from its surfaces to remain parallel to each other [15]. The self-compensation in the corner-cube mirror and the use of the DSM enable the interferometer to solve both the tilt of the moving plane mirror and the shear of a single corner-cube mirror. Moreover, compared with the corner-cube-mirror or cat’s-eye retroreflector, the smaller volume and lighter weight enable the DSM to have the benefit and potential to move short distances quite rapidly. Therefore, the use of specific electronics downstream will make the moving DSM suitable for rapid scan [11,15]. The optical path difference (OPD) is created by the straight reciprocating motion of the moving DSM driven by a linear actuator. The OPD value is four times the displacement l of the moving DSM from the zero path difference (ZPD) position. The light source is located at the front focal plane of the collimating lens, and the one-dimensional detector is located at the back focal plane of the collecting lens.

The UVS generates multiple interferograms simultaneously in one scan period of the moving DSM, each interferogram with a separate wavelength range and located in a separate pixel of the linear detector. More specifically, not only the grating spreads the spectral information onto a one-dimensional detector, but also the interferometer produces multiple interferograms simultaneously in one scan period of the moving DSM, each interferogram covering a separate wavelength range controlled by the grating and detector geometry, each interferogram located in a separate pixel of the detector. The UVS integrates interferometric and dispersive spectroscopy to get spectral information.

When measuring an ultraviolet-visible narrow-band or an infrared broad-band source, Fourier transform spectrometer can perform high spectral resolution measurements [19]. The UVS uses a grating to divide a broadband spectral range into many narrow bands, and then uses interferometry to achieve ultrahigh spectral resolution for each narrow band. Consequently, the UVS can achieve ultrahigh spectral resolution for a broadband spectral range in the ultraviolet-visible spectral region. By dispersing the light with a plane transmission grating instead of a prism, mainly because the grating can provide higher and more linear dispersion of the wavelength than the prism, and it is also a potential tradeoff with the throughput advantage of a typical Fourier transform spectrometer. The thickness of a plane transmission grating can be relatively small, so the geometrical length of the light path in a plane transmission grating can be smaller than that in a prism. Therefore, for the loss of light energy caused by material absorption, a plane transmission grating can be smaller than a prism when the same material is used.

For the UVS design, the center fringes are spread into multiple separate pixels (interferograms), each with a separate wavelength range, and therefore the dynamic range requirement of the detector is reduced [29].

Figure 2

Fig. 2 Equivalent light path diagram in the meridian plane of the UVS.

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shows the equivalent light path diagram in the meridian plane of the UVS. The grating equation for a plane transmission grating is given by [30]

m λ_{i} = d [n (λ_{i}) \sin α + \sin θ_{m} (λ_{i})] .

where

m

is the diffraction order that is an integer,

λ_{i}

is the wavelength of light,

d

is the groove spacing of grating,

n (λ_{i})

is the refractive index of the plane transmission grating for wavelength

λ_{i}

,

α

is the incidence angle measured from the grating normal,

θ_{m} (λ_{i})

is the m-order diffraction angle measured from the grating normal for wavelength

λ_{i}

.

Suppose that $f$ is the focal length of the collecting lens, $b$ is the pixel size of the detector, $λ_{c}$ is the central wavelength of the source spectra, $y (λ_{i})$ is the y-axis coordinate for wavelength $λ_{i}$ at the detector plane, and the y-axis coordinate for wavelength $λ_{c}$ at the detector plane is $y (λ_{c}) = 0$ . Let the optical axis of the collecting lens overlap with the diffracted light ray from the grating of the central wavelength. It can be obtained that

y (λ_{i}) = f \cdot \frac{τ (λ_{c}) \sqrt{1 - τ^{2} (λ_{i})} - τ (λ_{i}) \sqrt{1 - τ^{2} (λ_{c})}}{\sqrt{1 - τ^{2} (λ_{c})} \sqrt{1 - τ^{2} (λ_{i})} + τ (λ_{c}) τ (λ_{i})},

where

τ (λ) = \frac{λ}{d} - n (λ) \sin α .

The interferogram k located in pixel k of one-dimensional detector covers a wavelength range from $λ_{k 1}$ to $λ_{k j}$ which is determined by $| y (λ_{k j}) - y (λ_{k 1}) | \leq b$ . When the source spectrum covers a wavelength range from $λ_{\min}$ to $λ_{\max}$ (i.e., a wavenumber range from $σ_{\min} = 1 / λ_{\max}$ to $σ_{\max} = 1 / λ_{\min}$ ), the number of pixels of the one-dimensional detector is determined by

N \geq \frac{| y (λ_{\max}) - y (λ_{\min}) |}{b} .

For convenience, based on Nyquist criterion, the sampling interval for each interferogram produced by the UVS can be given as

X \leq \frac{1}{2 σ_{\max}} .

The interferogram $I (l)$ is given by

I (l) = \int_{0}^{\infty} B (σ) [1 + \cos (8 π σ l)] d σ .

where

l

is the displacement of the moving DSM from the ZPD position,

σ

is the wave number, and

B (σ)

is the input spectral intensity at a wavenumber

σ

.

The maximum OPD for each interferogram is

{OPD}_{\max} = 4 l_{\max} .

where

l_{\max}

is the maximum displacement of the moving DSM from the ZPD position.

The theoretical spectral resolution $δ σ$ of the UVS is

δ σ = \frac{1}{2 \cdot {OPD}_{\max}} = \frac{1}{8 l_{\max}} .

Considering the effect of the apodization (e.g. triangular function) of the interferogram, the desired spectral resolution of the UVS can be calculated by

δ σ^{'} = \frac{1}{4 l_{\max}} .

Suppose that $K$ is the number of sampling points for each unilateral interferogram. Based on Eqs. (5) and (7), it can be obtained that

K = 8 l_{\max} σ_{\max} .

The resolving power of the UVS is determined by the number of sampling points for the interferogram (i.e.,

R = σ_{\max} / δ σ = K

). For the spectrometer proposed in [17], the resolving power is determined by the number of pixels per row of the detector. The number of sampling points for the interferogram can be much larger than the number of pixels per row of the detector. Therefore, the resolving power of the UVS can be much higher than that of the spectrometer proposed in [17].

Table 1

Table 1. Comparisons of the UVS with Interferometry, Dispersive, and Color Filter Approaches

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shows both the main advantages and disadvantages of the UVS compared with other existing spectrometers.

3. Design calculation and numerical simulation

Suppose that the source spectrum covers a wavelength range from 250 nm to 450 nm, i.e., a wavenumber range from 22222.2 cm⁻¹ to 40000 cm⁻¹. The wavelength difference versus wavenumber difference for several wavelengths are shown in Table 2

Table 2. Wavelength Difference Versus Wavenumber Difference for Several Wavelengths

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. Based on Table 2, if the desired spectral resolution (in wavelength) of the UVS is 0.005 nm at 250 nm, 0.01 nm at 350 nm, together with 0.02 nm at 450 nm, the desired spectral resolution (in wavenumber) of the UVS should be

δ σ^{'} = 0.8 {cm}^{- 1}

. The theoretical spectral resolution of the UVS can be

δ σ = 0.4 {cm}^{- 1}

. Thus, the maximum displacement of the moving DSM from the ZPD position is

l_{\max} = 1 / (8 δ σ) = 1 / (4 δ σ^{'}) = 3.125 mm

. Accordingly, the number of sampling points for each interferogram is

K = 8 l_{\max} σ_{\max} = 8 \times 3.125 m m \times 40000 c m^{- 1} = 100000

.

A suitable material for the plane transmission grating in a UVS is Fused silica. The formula of refractive index for fused silica can be written as [31]

n^{2} = 1 + \frac{0.6961663 λ^{2}}{λ^{2} - {0.0684043}^{2}} + \frac{0.4079426 λ^{2}}{λ^{2} - {0.1162414}^{2}} + \frac{0.8974794 λ^{2}}{λ^{2} - {9.896161}^{2}} .

Suppose that $f = 100 mm$ , $b = 0.02 mm$ , $λ_{C} = 350 nm$ , $α = 10 °$ , and the transmission grating with 200 grooves/mm. From Eqs. (2), (3) and (11), the y-axis coordinate for wavelength $λ_{i}$ at the detector plane is shown in Fig. 3

Fig. 3 The y-axis coordinate of different wavelengths at detector plane.

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. From Eq. (4), the number of pixels of the one-dimensional detector must be greater than

| y (λ_{250}) - y (λ_{450}) | / b \approx (2.0646 + 2.0524) / 0.02 = 205.85

. Hence, 206 separate interferograms are obtained simultaneously in one scan period of the moving DSM. According to Eqs. (2), (3), (6), and (11) together with the above parameter values, several unilateral interferograms generated simultaneously by the UVS in one scan period of the moving DSM are shown in Fig. 4

Fig. 4 Several interferograms obtained simultaneously by the UVS.

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.

Figure 5

Fig. 5 UVS interferogram 1 containing merely wavelength 250, 250.005, 250.01, 250.015, 250.02 nm and its spectrum.

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shows the UVS interferogram 1 containing merely wavelength 250 nm, 250.005 nm, 250.01 nm, 250.015 nm, 250.02 nm and the spectrum obtained from Fourier transform of the interferogram 1 when the theoretical spectral resolution is 0.4 cm⁻¹. Five spectral peaks are clearly visible, so the spectral resolution of the UVS is at least 0.005 nm at 250 nm. Figure 6

Fig. 6 UVS interferogram 104 containing merely wavelength 349.98, 349.99, 350, 350.01, 350.02 nm and its spectrum.

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shows the UVS interferogram 104 containing merely wavelength 349.98 nm, 349.99 nm, 350 nm, 350.01 nm, 350.02 nm and the spectrum obtained from Fourier transform of the interferogram 104 when the theoretical spectral resolution is 0.4 cm⁻¹. Figure 7

Fig. 7 UVS interferogram 206 containing merely wavelength 449.92, 449.94, 449.96, 449.98, 450 nm and its spectrum.

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shows the UVS interferogram 206 containing merely wavelength 449.92 nm, 449.94 nm, 449.96 nm, 449.98 nm, 450 nm and the spectrum obtained from Fourier transform of the interferogram 206 when the theoretical spectral resolution is 0.4 cm⁻¹. It can be easily obtained that the spectral resolution of the UVS is at least 0.01 nm at 350 nm together with 0.02 nm at 450 nm.

4. Conclusion

An ultrahigh-resolution rapid-scan ultraviolet-visible spectrometer (UVS) is investigated. The first significant advantage of the UVS is that the multiplex disadvantage of ultraviolet-visible interferometry is greatly reduced by combining interferometric and dispersive spectroscopy. The second important advantage of the UVS is ultrahigh spectral resolution for a broadband spectral range in ultraviolet-visible spectral region. The third advantage is that the UVS will be able to achieve rapid-scan if specific electronics downstream is used. The fourth advantage of the UVS, compared with traditional interferometry, is that the dynamic range requirement of the detector is reduced. There are also the trade-offs for the UVS: (1) the presence of a moving part will reduce the stability against various disturbances, (2) the scanning nature will make the data collection time long and, therefore, make the UVS unsuitable for measuring the spectra from transient sources. Although no instrument or prototype is actually built or tested, and the calculations represent only the first-order optical effects (i.e., none of the aberrations of actual optical systems are present), the UVS is a unique design to greatly reduce the multiplex disadvantage of ultraviolet-visible multiplexed spectroscopy while achieving rapid-scan combined with ultrahigh spectral resolution for a wide spectral range (e.g., 0.005 nm at 250 nm, 0.01 nm at 350 nm together with 0.02 nm at 450 nm). The UVS will be suitable for ultrahigh-resolution ultraviolet-visible spectral measurement.

Funding

National Natural Science Foundation of China (NSFC) (61605151).

References

1. M. Abuleil and I. Abdulhalim, “Narrowband multispectral liquid crystal tunable filter,” Opt. Lett. 41(9), 1957–1960 (2016). [CrossRef] [PubMed]

2. O. I. Korablev, D. A. Belyaev, Y. S. Dobrolenskiy, A. Y. Trokhimovskiy, and Y. K. Kalinnikov, “Acousto-optic tunable filter spectrometers in space missions [Invited],” Appl. Opt. 57(10), C103–C119 (2018). [CrossRef] [PubMed]

3. T. Okamoto and I. Yamaguchi, “Simultaneous acquisition of spectral image information,” Opt. Lett. 16(16), 1277–1279 (1991). [CrossRef] [PubMed]

4. J. M. Mooney, V. E. Vickers, M. An, and A. K. Brodzik, “High-throughput hyperspectral infrared camera,” J. Opt. Soc. Am. A 14(11), 2951–2961 (1997). [CrossRef]

5. Q. Li, X. He, Y. Wang, H. Liu, D. Xu, and F. Guo, “Review of spectral imaging technology in biomedical engineering: achievements and challenges,” J. Biomed. Opt. 18(10), 100901 (2013). [CrossRef] [PubMed]

6. N. Hagen and M. W. Kudenov, “Review of snapshot spectral imaging technologies,” Opt. Eng. 52(9), 090901 (2013). [CrossRef]

7. Q. Yang, “Static broadband snapshot imaging spectrometer,” Opt. Eng. 52(5), 053003 (2013). [CrossRef]

8. Q. Yang, “Compact static infrared broadband snapshot imaging spectrometer,” Chin. Opt. Lett. 12(3), 031201 (2014). [CrossRef]

9. Q. Yang, “Compact high-resolution Littrow conical diffraction spectrometer,” Appl. Opt. 55(18), 4801–4807 (2016). [CrossRef] [PubMed]

10. W. H. Steel, Interferometry (Cambridge University Press, 1983).

11. C. M. Snively, S. Katzenberger, G. Oskarsdottir, and J. Lauterbach, “Fourier-transform infrared imaging using a rapid-scan spectrometer,” Opt. Lett. 24(24), 1841–1843 (1999). [CrossRef] [PubMed]

12. J. Kauppinen, J. Heinonen, and I. Kauppinen, “Interferometers based on the rotational motion,” Appl. Spectrosc. Rev. 39(1), 99–130 (2004). [CrossRef]

13. R. K. Chan, P. K. Lim, X. Wang, and M. H. Chan, “Fourier transform ultraviolet-visible spectrometer based on a beam-folding technique,” Opt. Lett. 31(7), 903–905 (2006). [CrossRef] [PubMed]

14. P. R. Griffiths and J. A. de Haseth, Fourier Transform Infrared Spectrometry (Wiley-Interscience, 2007).

15. Q. Yang, B. Zhao, and D. Wen, “Principle and analysis of a moving double-sided mirror interferometer,” Opt. Laser Technol. 44(5), 1256–1260 (2012). [CrossRef]

16. M. W. Kudenov and E. L. Dereniak, “Compact real-time birefringent imaging spectrometer,” Opt. Express 20(16), 17973–17986 (2012). [CrossRef] [PubMed]

17. Q. Yang, “Coherent-dispersion spectrometer for the ultraviolet and visible regions,” Opt. Express 26(10), 12372–12386 (2018). [CrossRef] [PubMed]

18. Q. Yang, “Broadband high-spectral-resolution ultraviolet-visible coherent-dispersion imaging spectrometer,” Opt. Express 26(16), 20777–20791 (2018). [CrossRef] [PubMed]

19. A. Barducci, D. Guzzi, C. Lastri, P. Marcoionni, V. Nardino, and I. Pippi, “Theoretical aspects of Fourier Transform Spectrometry and common path triangular interferometers,” Opt. Express 18(11), 11622–11649 (2010). [CrossRef] [PubMed]

20. T. Hirschfeld, “Fellgett’s advantage in UV-VIS multiplex spectroscopy,” Appl. Spectrosc. 30(1), 68–69 (1976). [CrossRef]

21. P. Luc and S. Gerstenkorn, “Fourier transform spectroscopy in the visible and ultraviolet range,” Appl. Opt. 17(9), 1327–1331 (1978). [CrossRef] [PubMed]

22. E. Voigtman and J. D. Winefordner, “The multiplex disadvantage and excess low-frequency noise,” Appl. Spectrosc. 41(7), 1182–1184 (1987). [CrossRef]

23. A. Barducci, D. Guzzi, C. Lastri, V. Nardino, P. Marcoionni, and I. Pippi, “Radiometric and signal-to-noise ratio properties of multiplex dispersive spectrometry,” Appl. Opt. 49(28), 5366–5373 (2010). [CrossRef] [PubMed]

24. P. Mouroulis, R. O. Green, and D. W. Wilson, “Optical design of a coastal ocean imaging spectrometer,” Opt. Express 16(12), 9087–9096 (2008). [CrossRef] [PubMed]

25. S. Pacheco and R. Liang, “Snapshot, reconfigurable multispectral and multi-polarization telecentric imaging system,” Opt. Express 22(13), 16377–16385 (2014). [CrossRef] [PubMed]

26. A. Weisberg, J. Craparo, R. De Saro, and R. Pawluczyk, “Comparison of a transmission grating spectrometer to a reflective grating spectrometer for standoff laser-induced breakdown spectroscopy measurements,” Appl. Opt. 49(13), C200–C210 (2010). [CrossRef]

27. C. Wang, Z. Ding, S. Mei, H. Yu, W. Hong, Y. Yan, and W. Shen, “Ultralong-range phase imaging with orthogonal dispersive spectral-domain optical coherence tomography,” Opt. Lett. 37(21), 4555–4557 (2012). [CrossRef] [PubMed]

28. W. Bao, Z. Ding, P. Li, Z. Chen, Y. Shen, and C. Wang, “Orthogonal dispersive spectral-domain optical coherence tomography,” Opt. Express 22(8), 10081–10090 (2014). [CrossRef] [PubMed]

29. J. V. Sweedler, R. D. Jalkian, G. R. Sims, and M. B. Denton, “Crossed interferometric dispersive spectroscopy,” Appl. Spectrosc. 44(1), 14–20 (1990). [CrossRef]

30. C. Palmer and E. Loewen, Diffraction Grating Handbook (Newport Corporation, 2005).

31. M. Bass, G. Li, and E. V. Stryland, Handbook of Optics (McGraw-Hill, 2010).

	Advantages of the UVS	Disadvantages of the UVS
UVS versus coherent-dispersion spectrometer in [17]	1. Ultrahigh spectral resolution	1. Stability against various disturbances is low 2. Data collection time is long 3. Not suitable for measuring transient sources
UVS versus temporal interferometry based on linear motion (e.g. moving corner-cube-mirror interferometer)	1. The multiplex disadvantage inherent in ultraviolet-visible interferometry is greatly reduced. 2. The dynamic range requirement of the detector is reduced. 3. Higher spectral resolution for measuring a broadband source in the ultraviolet-visible spectral region. 4. The moving DSM has the smaller volume and lighter weight.
UVS versus temporal interferometry based on rotational motion	1. The multiplex disadvantage inherent in ultraviolet-visible interferometry is greatly reduced. 2. The dynamic range requirement of the detector is reduced. 3. High spectral resolution	1. Stability against various disturbances is slightly lower
UVS versus spatial interferometry	1. The multiplex disadvantage inherent in ultraviolet-visible interferometry is greatly reduced. 2. The dynamic range requirement of the detector is reduced. 3. High spectral resolution	1. Stability against various disturbances is low 2. Data collection time is long 3. Not suitable for measuring transient sources
UVS versus traditional dispersive spectrometer	1. High spectral resolution for a broadband spectral range.	1. Stability against various disturbances is low 2. Data collection time is long 3. Not suitable for measuring transient sources
UVS versus color filter spectrometer	1. High spectral resolution for a broadband spectral range.	1. Stability against various disturbances is low 2. Data collection time is long

Wavelength	Wavenumber	Wavelength difference	Wavenumber difference
249.995 nm	40000.8 cm⁻¹
250 nm	40000 cm⁻¹	250 - 249.995 = 0.005 nm	40000.8 - 40000 = 0.8 cm⁻¹
250.005 nm	39999.2 cm⁻¹	250.005 - 250 = 0.005 nm	40000 - 39999.2 = 0.8 cm⁻¹
349.99 nm	28572.2 cm⁻¹
350 nm	28571.4 cm⁻¹	350 - 349.99 = 0.01 nm	28572.2 - 28571.4 = 0.8 cm⁻¹
350.01 nm	28570.6 cm⁻¹	350.01 - 350 = 0.01 nm	28571.4 - 28570.6 = 0.8 cm⁻¹
449.98 nm	22223.2 cm⁻¹
450 nm	22222.2 cm⁻¹	450 - 449.98 = 0.02 nm	22223.2 - 22222.2 = 1 cm⁻¹
450.02 nm	22221.2 cm⁻¹	450.02 - 450 = 0.02 nm	22222.2 - 22221.2 = 1 cm⁻¹

	Advantages of the UVS	Disadvantages of the UVS
UVS versus coherent-dispersion spectrometer in [17]	1. Ultrahigh spectral resolution	1. Stability against various disturbances is low 2. Data collection time is long 3. Not suitable for measuring transient sources
UVS versus temporal interferometry based on linear motion (e.g. moving corner-cube-mirror interferometer)	1. The multiplex disadvantage inherent in ultraviolet-visible interferometry is greatly reduced. 2. The dynamic range requirement of the detector is reduced. 3. Higher spectral resolution for measuring a broadband source in the ultraviolet-visible spectral region. 4. The moving DSM has the smaller volume and lighter weight.
UVS versus temporal interferometry based on rotational motion	1. The multiplex disadvantage inherent in ultraviolet-visible interferometry is greatly reduced. 2. The dynamic range requirement of the detector is reduced. 3. High spectral resolution	1. Stability against various disturbances is slightly lower
UVS versus spatial interferometry	1. The multiplex disadvantage inherent in ultraviolet-visible interferometry is greatly reduced. 2. The dynamic range requirement of the detector is reduced. 3. High spectral resolution	1. Stability against various disturbances is low 2. Data collection time is long 3. Not suitable for measuring transient sources
UVS versus traditional dispersive spectrometer	1. High spectral resolution for a broadband spectral range.	1. Stability against various disturbances is low 2. Data collection time is long 3. Not suitable for measuring transient sources
UVS versus color filter spectrometer	1. High spectral resolution for a broadband spectral range.	1. Stability against various disturbances is low 2. Data collection time is long

Wavelength	Wavenumber	Wavelength difference	Wavenumber difference
249.995 nm	40000.8 cm⁻¹
250 nm	40000 cm⁻¹	250 - 249.995 = 0.005 nm	40000.8 - 40000 = 0.8 cm⁻¹
250.005 nm	39999.2 cm⁻¹	250.005 - 250 = 0.005 nm	40000 - 39999.2 = 0.8 cm⁻¹
349.99 nm	28572.2 cm⁻¹
350 nm	28571.4 cm⁻¹	350 - 349.99 = 0.01 nm	28572.2 - 28571.4 = 0.8 cm⁻¹
350.01 nm	28570.6 cm⁻¹	350.01 - 350 = 0.01 nm	28571.4 - 28570.6 = 0.8 cm⁻¹
449.98 nm	22223.2 cm⁻¹
450 nm	22222.2 cm⁻¹	450 - 449.98 = 0.02 nm	22223.2 - 22222.2 = 1 cm⁻¹
450.02 nm	22221.2 cm⁻¹	450.02 - 450 = 0.02 nm	22222.2 - 22221.2 = 1 cm⁻¹

Ultrahigh-resolution rapid-scan ultraviolet-visible spectrometer

Abstract

1. Introduction

2. Principle

3. Design calculation and numerical simulation

4. Conclusion

Funding

References

Cited By

Figures (7)

Tables (2)

Equations (11)

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