21 November 2017 Grism and immersion grating for space telescope
Author Affiliations +
Proceedings Volume 10568, International Conference on Space Optics — ICSO 2004; 105681M (2017) https://doi.org/10.1117/12.2308014
Event: International Conference on Space Optics 2004, 2004, Toulouse, France
Abstract
The grism is a versatile dispersion element for an astronomical instrument ranging from ultraviolet to infrared. Major benefit of using a grism in a space application, instead of a reflection grating, is the size reduction of optical system because collimator and following optical elements could locate near by the grism. The surface relief (SR) grism is consisted a transmission grating and a prism, vertex angle of which is adjusted to redirect the diffracted beam straight along the direct vision direction at a specific order and wavelength. The volume phase holographic (VPH) grism consists a thick VPH grating sandwiched between two prisms, as specific order and wavelength is aligned the direct vision direction. The VPH grating inheres ideal diffraction efficiency on a higher dispersion application. On the other hand, the SR grating could achieve high diffraction efficiency on a lower dispersion application. Five grisms among eleven for the Faint Object Camera And Spectrograph (FOCAS) of the 8.2m Subaru Telescope with the resolving power from 250 to 3,000 are SR grisms fabricated by a replication method. Six additional grisms of FOCAS with the resolving power from 3,000 to 7,000 are VPH grisms. We propose “Quasi-Bragg grism” for a high dispersion spectroscopy with wide wavelength range.

The germanium immersion grating for instance could reduce 1/64 as the total volume of a spectrograph with a conventional reflection grating since refractive index of germanium is over 4.0 from 1.6 to 20 μm. The prototype immersion gratings for the mid-InfraRed High dispersion Spectrograph (IRHS) are successfully fabricated by a nano-precision machine and grinding cup of cast iron with electrolytic dressing method.

1.

Introduction

The direct vision grating, namely, the grism (Fig. 1b) is a versatile dispersion element for an astronomical observations ranging from ultraviolet to infrared. Major benefit of using a grism in a space application, instead of a reflection grating (Fig. 1a), is the size reduction of optical system because collimator and following optical elements could locate near by the grism (Fig.2). Moreover, the grism has the possibility for allowing flexible switching between imaging and spectroscopic mode by simply inserting or removing the grism in the optical pass.

Fig. 1.

Gratings

00132_PSISDG10568_105681M_page_2_1.jpg

Fig. 2

Size comparison of grating spectrographs.

00132_PSISDG10568_105681M_page_2_2.jpg

The immersion grating (Fig. 1c) is filled up a dielectric medium in its optical pass and the angular dispersion of the grating is proportional to the refractive index of the medium. The total volume of a spectrograph could dramatically reduce by means of an immersion grating since the volume of the spectrograph is inversely proportional to the cubic of the refractive index of the grating media.

We introduce function of grism and immersion grating and the fabrication methods on gratings developed for instruments of the 8.2m Subaru Telescope on Mauna Kea, Hawaii [1-3].

2.

Grism

2.1.

Surface relief grism

As shown in figure 3 left, a surface relief (SR) grism is consisted a transmission grating and prism, vertex angle of which is adjusted to redirect the diffraction beam straight along the direct vision direction at a specific order and wavelength. This type of grism has been used for astronomical instruments until multichannel detectors such as a CCD had developed. Especially, a replica of a blazed grating is generally used for a low dispersion grism of visible and near infrared instruments because it is moderate prices and sufficient diffraction efficiency for general purpose [4]. However, as groove period of a SR grating is close to functional wavelength, diffraction efficiency behaves peculiarly. The cause of the phenomena is an electromagnetic coupling of higher order diffraction and periodic grating structure, namely, anomaly. Figure 3 right shows calculated and measured diffraction efficiency versus normalized period of a SR transmission grating with refractive index of 1.5. The calculations are carried out by means of the analysis program valid for gratings of the rigorous coupled-wave analysis (RCWA) method [5]. The efficiency of the SR grating become oscillatory decrease below 5 and steeply drops at 2 in normalized groove period. Measured efficiencies of SR grisms (closed dots) are compatible with the efficiency cave of the RCWA calculation.

Fig. 3

Schematic representation (left) and diffraction efficiency (right) of surface relief grism.

00132_PSISDG10568_105681M_page_3_1.jpg

The grism with higher order diffractions, that is, Echelle type grism are used for the high dispersion spectrograph on astronomical observations. High index material is employed for the prism of a high dispersion grism if the grism size is limited by space of an instrument since dispersion is proportional to optical path difference caused by the grating (Fig. 1). However when a grism consists of a high index prism and replicated grating, the vertex angle of the prism is limited by a critical angle between the high index material and resin of replica. Refractive indices of the prism and replica of a SR grism are 2.3 and 1.5 respectively for example, and a ray enters vertically from the prism side, the critical angle is 40.7 degree, that is, a vertex angle of the prism has to be smaller than the critical angle. In the case of the grism tilts to clockwise in figure 3 left, critical angle becomes larger, and optical axes are sifted in parallel between the incident and exit ray on the grism. The following optics of an instrument becomes lager to avoid the vignetting at a result of the optical axes shift. In these reason, a SR grism with high dispersion is essentially grooved directly onto a high index material that is called a solid grating.

2.2.

Volume phase holographic grism

The volume phase holographic (VPH) grism consists a thick VPH grating sandwiched between two prisms as specific order and wavelength is aligned the direct vision direction (Fig. 4 left). As show in figure 4 right, a thick VPH grating archives very high efficiency from 1 to 5 in normalized period of index modulation [5]. In the case of the VPH grism, refractive indices of prisms and VPH grating are 2.3 and 1.5 respectively α is obtained 63.6 degree from Eq.4 in Appendix A. As mentioned in subsection 2.1, the vertex angle of the prism is limited by the critical angle between a grating replica and prism. It means that a VPH grism has capability of higher dispersion spectroscopic observations compared with a SR grism. However a thick volume phase grating was very difficult to fabrication owing to recoding media. Dichromate gelatin had been the unique recording media for a thick volume phase hologram in practical use [6], preparation of recording material and development are complicated and critical because they are wet process.

Fig. 4

Schematic representation (left) and diffraction efficiency (right) of volume phase holographic grism.

00132_PSISDG10568_105681M_page_3_2.jpg

We applied a photosensitive resin developed by Nippon Paint Co.Ltd. as a recording material of VPH grating. The photosensitive resin could overcome the disadvantages of dichromate gelatin [7-8]. The photosensitive resin consists of radically polymerizable monomer (RPM) with higher refractive, cationically polymerizable monomer (CPM) with lower refractive index, dyes, and photo-initiator. By accepting the radical from dyes absorbed visible light (470-600nm), the RMP is polymerized (Fig.7). Consequently, the monomer of RMP produces the concentration gradients at the boundary between the polymerized part and the unpolymerized part. Because of monomer diffusion, the refractive index of the polymerized part becomes higher. RPM and CPM are simultaneously polymerized by the photo-initiator with ultraviolet irradiation, and the refractive index modulation is fixed.

Fig. 5

Schematic representation (above) and picture (below) of optical system for VPH grating exposure.

00132_PSISDG10568_105681M_page_4_1.jpg

2.3.

Grisms for Subaru Telescope

Several types of diffraction grating are developed for instruments of the 8.2m Subaru Telescope on Mauna Kea, Hawai [9-11]. Trispec grisms for visible, J-H band and K band were made by replication. The solid grism of Cytop (fluorocarbon polymers) for the Coronagraphic Imager with Adaptive Optics (CIAO) with the resolving power of 600 at near infrared had been successfully fabricated by using a 3D profiling machine with nano-precision and diamond turning method. The Cytop is transparent from 200 to 2,500 nm. Moreover, a solid grism of gallium arsenide (GaAs) or ZnSe with higher dispersion for CIAO ranging from 0.9 to 5 μm are under developing. The Faint Object Camera And Spectrograph (FOCAS) is providing eleven grisms with the resolving power from 250 to 7,000 [12-16].

2.4.

FOCAS grisms

The physical size of a FOCAS grism is 110 by 106 in mm, the maximum thickness along the optical axis is 106 mm. Five FOCAS grisms among eleven were made by replication onto a prism of conventional optical glass (Fig.6 right to center left) and residual six are VPH grisms (Fig.6 left). Grisms of high dispersion with the first diffraction order were fabricated by replication. However, measured efficiencies of the grisms are 45 to 48 % at the each blazed wavelength as the result of anomaly (Fig. 3 left, Normalized period: 2.70 and 2.78). The value could not be sufficient for the specifications of FOCAS.

Fig. 6

FOCAS grisms. From right, replicated grisms with low dispersion (R=500 with 0.4” slit), middle dispersion (R=1,400) and Echelle type (higher order diffraction) with high dispersion (R=3,000), VPH grism with high dispersion (R=3,000)

00132_PSISDG10568_105681M_page_4_3.jpg

We employed VPH grisms (Fig. 4 left) for the high (R=3,000) and very high (R=7,000) dispersion grisms of FOCAS with the first diffraction order because a VPH grating is suitable for a higher dispersion application as shown in figure 4 right [5]. The VPH grism with high dispersion consist of a VPH grating two prisms of a conventional optical glass (Fig. 6 left). The very high dispersion grisms with the first order diffraction consist of a VPH grating and two high-index prisms of zinc selenide (ZnSe, n=2.6) as shown in figure 7.

Fig. 7

ZnSe VPH grism for FOCAS with very high dispersion (R=7,000).

00132_PSISDG10568_105681M_page_4_2.jpg

2.5.

Quasi-Bragg grism

The VPH grating inheres ideal diffraction efficiency on a higher dispersion spectroscopy at a specific wavelength region, otherwise, diffraction efficiencies decrease on higher order diffractions. We propose an grism consists a comb like grating (Fig. 8), we called quasi-Bragg grating, and two high-index prisms. The quasi-Bragg grism has both advantage of VPH and Echell type grism (Fig. 9) [17-18]. We are developing a comb like grating by means of semiconductor process.

Fig. 8

Schematic representation of “Quasi-Bragg grating”.

00132_PSISDG10568_105681M_page_4_4.jpg

Fig. 9

Calculation result of diffraction efficiencies of Quasi-Bragg grating [18]. (Al refractor, d=15.27 μm, A =5.71 μm, w=0.029 μm, ng = 1.50, Bragg angle: θB = 20.51deg)

00132_PSISDG10568_105681M_page_4_5.jpg

3.

Immersion Grating

3.1.

Mid-infrared high dispersion spectrograph

IRHS is under planning design study as a next generation instrument for the 8.2m Subaru telescope. IRHS is aiming resolving power of R= λ/Δλ= 200,000 at 10μm, in order to observe vibrational transitions of molecule in circum-stellar and dark clouds for instance. Such a high dispersion spectrograph requires a dispersing element or moving mirror with minimum 2m in an optical path difference. A Fourier transform spectrometer (FTS) is usually applied as a high dispersion spectrometer for laboratory use from middle to far infrared because of the small size and low cost of the instrument compared with a grating spectrometer. Although FTS has disadvantages with background noise and atmospheric turbulence, only several tens or hundreds astronomical objects in the total sky can be observed around 10 μm. On the other hand, a midinfrared high dispersion spectrograph with a conventional grating of reflection type (Fig. 1a) as the dispersing element requires a large optical installation. Since a collimated beam of 40cm in diameter should be used for the conventional grating spectrograph with a resolving power of 200,000 at 10μm, the total volume of the instrument covered with a cooled vacuum chamber (below 50K) is nearly 100m3. It is huge enough even for the Nathmith focus of the Subaru telescope.

3.2.

Trial fabrications for solid gratings

The germanium immersion grating for instance could reduce 1/64 as the total volume of a spectrograph with a conventional reflection grating since refractive index of germanium is over 4.0 from 1.6 to 20μm. The size of IRHS become 2m3 covered with a cooled vacuum chamber [19]. The immersion grating is not only a powerful dispersion element for grand-based applications, but also an ideal dispersion element for space applications (Fig.10).

Fig. 10

Mid-infrared high dispersion spectrograph with R=100,000@10μm for SPICA (3.5m space infrared observatory)

00132_PSISDG10568_105681M_page_5_1.jpg

In order to fabricate a solid grating with a high index material, numerous studies on micro-machining methods have been carried out by researchers and engineers. These include a precise ruling-engine, anisotropic chemical etching and so on [20-24]. To our knowledge, the KRS-5 grism used for near to middle infrared can be fabricated by using a precise ruling-engine [23]. However, since KRS-5 is a mixed crystal of TlBr and TlI, a homogeneous and large block is difficult to grow.

We had also performed trials of various methods for grating fabrications, resinous bonded diamond grinding, ion etching (Fig. 11) and laser ablation (Fig. 12) [25-27], for example. However solid gratings with deep grooves exceed 1μm in depth, are difficult to fabricate with these methods. Finally, we had successfully fabricated an immersion grating for the prototype IRHS by using a 3D profile grinding/turning machine with nano precision and grinding cups of cast iron with electrolytic dressing method (Fig. 13, 14) [28-31].

Fig. 11

Lithium niobate grism fabricated by oblique ion etching (left) and cross section of the grism (right).

00132_PSISDG10568_105681M_page_5_2.jpg

Fig. 12

Schematic representation of grating fabrication by laser abrasion (left) and SEM picture of germanium grooves fabricated by laser abrasion (right).

00132_PSISDG10568_105681M_page_5_3.jpg

Fig. 13

Fabrication of germanium immersion grating by means of nano-precision machine (left) and picture of prototype immersion grating for IRHS (right).

00132_PSISDG10568_105681M_page_6_1.jpg

Fig. 14

Grooves shape of immersion grating fabricated by grinding cups of cast iron and electrolytic dressing method.

00132_PSISDG10568_105681M_page_6_2.jpg

3.3.

Fabrication of immersion grating

The immersion gratings of prototype IRHS were designed for a spectrograph with a resolving power of 50,000 at 10μm or 250,000 at 2.0μm. The sizes of the prototype immersion gratings are 30 x 30 mm, 72mm in length and vertex angle of 68.75 degree. Groove spacing are 100μm for the first, 250μm for the second and third, 600μm for the forth and fifth fabrications. The grooves are slightly tilted to the incident aperture of the gratings to avoid influence of reflection at the incident aperture. The material of the immersion grating was germanium single crystal except the third fabrication. At the third fabrication, GaAs single crystal was chosen for the immersion grating because it was planed to use for a near infrared spectrograph, and GaAs is transparent from 0.9μm and its refractive index is about 3.4 at 1.0μm.

The wave front error of the fourth and fifth grating are acceptable for a prototype immersion grating at 10 μm if the maximum value of wave front error inside germanium is set up one eighth wave in rms, that is, 312.5nm in the air. We had obtained doubtful values of transmittance measured by using a conventional spectrophotometer because grooves are tilted about 0.8 degree to the incident aperture, and an incident and exit ray are angled about 3.2 degrees at a groove. We could say that the diffraction efficiency of the third, fourth and fifth gratings are at least 30% from 2 to 16 μm. Accurate diffraction efficiencies of gratings will measure by the prototype IRHS of under construction.

Figure 15 shows measurement for far field images of a diffraction beam. A beam of the CO2 laser as a light source at 10.6 μm was transformed to a Gaussian beam by means of a spatial filter. Figure 16 shows the cross sections of the far field images of an incident aperture and the diffraction beams of the gratings mentioned above. The dotted line is a far field image of the reflected beam of the incident aperture. The solid lines are the far field images of diffracted beams of immersed grooves. The FWHM of the ideal image for the measurement system is 220μm. The FWHM of the images of the third, fourth and fifth gratings are 280, 259 and 302μm respectively. The far field image of the third grating has side lobes with large amplitude caused by fatal wave front error. The FWHM of far field images of the fourth grating expands 18% which is compared with the ideal image, and it is seen a Roland ghost which amplitude is about 17% of the main lobe. The FWHM of the fifth grating expands 37%, and it is seen a Roland ghost which amplitude is about 14% of the main lobe. The expansion and Roland ghost implies a wave front error with large scale of a grating, that is, a deviation of the groove interval.

Fig. 15

Measurement of far-field image of immersion grating.

00132_PSISDG10568_105681M_page_6_3.jpg

Fig. 16

Cross section of far-field image of immersion gratings. No. 4: R=44,000@10μm.

00132_PSISDG10568_105681M_page_6_4.jpg

4.

Conclusion

The SR grism is suitable for low dispersion spectroscopy with wide wavelength range, while the VPH grism is an ideal dispersing element for high dispersion spectroscopy with a specific wavelength region. Furthermore the “Quasi-Bragg grism” will open up high dispersion spectroscopy with wide wavelength range.

Although further improvement for the wave front profile should be done, the results of the trial fabrication suggest that a geranium immersion grating used at around 10 μm can be realized by means of a 3D profile grinding/turning machine with nano precision and grinding cups of cast iron with electrolytic dressing method.

5.

APENDIX A

As shown in figure 4, Snell’s equation of refraction for the incident surface and boundary between prism and VPH grating of the VPH grism are given by

00132_PSISDG10568_105681M_page_7_1.jpg
00132_PSISDG10568_105681M_page_7_2.jpg

In the case of critical angle, θ2 is right angle, that is, sin θ2 is 1.0 and then Eq.2 is rewritten as:

00132_PSISDG10568_105681M_page_7_3.jpg

From Eq.3, Eq.1 is rewritten as:

00132_PSISDG10568_105681M_page_7_4.jpg

6.

6.

REFERENCES

1. 

N. Ebizuka, K. Oka, A. Yamada, M. Ishikawa, M. Kashiwagi, K. Kodate, Y. Hirahara, S. Sato, W. Fuji, M. Wakaki, K.S. Kawabata, M. Watanabe, H. Suto, M. Tamura and M. Iye, “Grism and Immersion Grating for the 8.2m Subaru Telescope”, Diffractive Optics 2003, 118–119, 2003.Google Scholar

2. 

N. Ebizuka, H. Kobayashi, Y. Hirahara, M. Wakaki, K. Kawaguchi, T. Sasaki and M. Iye “Development of grisms and immersion gratings for the spectrographs of the Subaru Telescope” Imaging the Universe in Three Dimensions, eds. W. van Breugel and J. Bland-Hawthorn, A.S.P. Conf. Ser., 195, 564–567, 1999.Google Scholar

3. 

N. Ebizuka, M. Iye, T. Sasaki and M. Wakaki, “Development of High dispersion grisms and immersion gratings for spectrographs of Subaru Telescope”, Proc. SPIE, 3355, 409–416, 1998Google Scholar

4. 

Design and Applications Handbook Photonics 1995 pp.H–372Google Scholar

5. 

K. Oka, W. Klaus, M. Fujino, M. Watanabe, N. Ebizuka and K. Kodate, “Rigorous Analysis of a Volume Phase Holographic Grism for Astronomical Observations”, Congress of International Communication for optics (ICO), 19, 565–566, 2002.Google Scholar

6. 

S.C. Barden, J.A. Arns, W.S. Colburn and J.B. Williams, “Volume-Phase Holographic Gratings and the Efficiency of Three Simple Volume-Phase Holographic Gratings”, Publ. Astron. Soc. Pacific, 112, 809–820, 2001Google Scholar

7. 

M. Kawabata, A. Sato, I. Sumiyoshi and T. Kubota, “Photopolymer system and its application to color hologram”, Appl. Opt. 33, 2152–2156, 1994.Google Scholar

8. 

K. Oka, A. Yamada, Y. Komai, E. Watanabe, N. Ebizuka, T. Teranishi, M. Kawabata and K. Kodate, “Optimization of a Volume Phase Holographic Grism for Astronomical Observation using the Photopolymer”, Proc. SPIE, 5005, 8–19, 2003.Google Scholar

9. 

N. Kaifu, “Subaru telescope”, Proc. SPIE, 3352, 14–22, 1998.Google Scholar

10. 

N. Kaifu et al., “The First Light of the Subaru Telescope: A New Infrared Image of the Orion Nebula”, Publ. Astron. Soc. Jpn., 52, 1–8 and Plate 1–5, 2000.Google Scholar

11. 

M. Iye et al., “Subaru first-light deep photometry of galaxies in A851 field”, Publ. Astron. Soc. Jpn., 52, 9–24, 2000.Google Scholar

12. 

N. Kashikawa, M. Inata, M. Iye, K. Kawabata, K. Okita, G. Kosugi, Y. Ohyama, T. Sasaki, K. Sekiguchi, T. Takata, Y. Shimizu, M. Yoshida, K. Aoki, Y. Saito, R. Asai, H. Taguchi, N. Ebizuka, T. Ozawa, Y. Yadoumaru, “FOCAS: Faint Object Camera and Spectrograph for the Subaru Telescope”, Proc. SPIE, 4008, 104–113, 2000.Google Scholar

13. 

Y. Ohyama, M. Yoshida, T. Takata, M. Imanishi, T. Usuda, Y. Saito, H. Taguchi, N. Ebizuka, F. Iwamuro, K. Motohara, T. Taguchi, T. Hata, T. Maihara, M. Iye, T. Sasaki, G. Kosugi, R. Ogasawara, J. Noumaru, Y. Mizumoto, M. Yagi and Y. Chikada, “Superwind-Driven Intense H2 Emission in NGC 6240”, Publ. Astron. Soc. Jpn, 52, 563–576 and Plate 43–44, 2000.Google Scholar

14. 

K.S. Kawabata, N. Ebizuka, T. Sasaki, K. Sekiguchi, M. Iye, K. Aoki, R. Asai, M. Inata, N. Kashikawa, G. Kosugi, T. Misawa, Y. Ohyama, K. Okita, T. Ozawa, Y. Saito, Y. Shimizu, H. Taguchi, T. Takata, Y. Yadoumaru, M. Yoshida, “Properties of FOCAS optical components”, Proc. SPIE, 4841, 1219–1228, 2003.Google Scholar

15. 

N. Ebizuka, K. Oka, A. Yamada, M. Watanabe, K. Shimizu, K. Kodate, M. Kawabata, T. Teranishi, K.S. Kawabata, M. Iye, “Development of Volume Phase Holographic (VPH) Grism for Visible to Near Infrared Instruments of the 8.2m Subaru Telescope”, Proc. SPIE, 4842, 319–328, 2003.Google Scholar

16. 

A. Yamada, K. Oka, M. Ishikawa, M. Kashiwagi, K. Kodate, N. Ebizuka and T. Teranishi, “Spectroscopic Observation for the Subaru Telescope”, Diffractive Optics 2003, 110–111, 2003.Google Scholar

17. 

K. Oka, N. Ebizuka and K. Kodate, “Rigorous Analysis of a Quasi-Bragg Diffraction Grating for Astronomical Observation”, Diffractive Optics 2003, 46–47, 2003.Google Scholar

18. 

K. Oka, N. Ebizuka and K. Kodate, “Optimal design of the grating with reflective plate of comb type for astronomical observation using RCWA”, Proc. SPIE, 5290, in press, 2004.Google Scholar

19. 

H. Tokoro, M. Atarashi, M. Omori, T. Machida, S. Hirabayashi, H. Kobayashi, Y. Hirahara, T. Masuda, N. Ebizuka and K. Kawaguchi, “Development of a mid-infrared high dispersion spectrograph (IRHS) for the Subaru telescope”, Proc. SPIE, 4841, 1016–1025, 2003.Google Scholar

20. 

H. Dekker, “An Immersion Grating for an Astronomical Spectrograph”, Instrumentation for Ground-Based Optical Astronomy, Present and Future, ed, L.B. Robinson, IGBO.conf. 183, 183–188, 1988.Google Scholar

21. 

G. Wiedemann and D.E. Jennings, “Immersion grating for infrared astronomy”, Appl. Opt., 32, 1176–1178, 1993.Google Scholar

22. 

H.U. Kaufl and B. Delabre, “Improved Design and Prototyping for a 10/20 mm Camera/Spectro-meter for ESO’s VLT”, Proc. SPIE, 2198, 1036–1046, 1994.Google Scholar

23. 

M. Shure, D, W, Toomey, J.T. Rayner, P.M. Onaka and A.T. Denault, “NSFCAM: a new infra-red array camera for the NASA Infrared Telescope Facility”, Proc. SPIE, 2198, 614–622, 1994.Google Scholar

24. 

L. Weitzel, A. Krabbe, H. Kroker, N. Thatte, L.E. Tacconi-Garman, M. Cameron and R. Genzel, “3D: The next generation near-infrared imaging spectrometer”, Astron. Astrophys. Suppl. Ser. 119, 531–546, 1996.Google Scholar

25. 

N. Ebizuka, M. Iye and T. Sasaki, “Optically Anisotropic Crystalline Grisms for Astronomical Spectrographs”, Appl.Opt. 37, 1236–1242, 1998.Google Scholar

26. 

Y. Aoyagi and S. Nanba, “Blazed ion-etched holographic gratings” Optica Acta 23, 701–707, 1976.Google Scholar

27. 

P.T. Rumsby, E.C. Harvey and D.W. Thomas, “Laser Microprojection for Micromechanical Device Fabrication”, Proc. SPIE, 2921, 684–692, 1996.Google Scholar

28. 

N. Ebizuka, S. Morita, T. Shimizu, Y. Yamagata, H. Omori, M. Wakaki, H. Kobayashi, H. Tokoro, Y. Hirahara, “Development of Immersion Grating for Mid-Infrared High Dispersion Spectrograph for the 8.2m Subaru Telescope”, Proc. SPIE, 4842, 293–300, 2003.Google Scholar

29. 

H. Ohmori, N. Ebizuka, S. Morita, Y. Yamagata, “Ultraprecision micro-grinding of germanium immersion grating element for mid-infrared super dispersion spectrograph”, CIRP 51st General Assembly, 221–224, 2001.Google Scholar

30. 

N. Ebizuka, S. Morita, Y. Yamagata, H. Ohmori, K. Kawaguchi, M. Wakaki, H. Kobayashi, Y. Hirahara, “Mid-infrared high dispersion spectrograph (IHRS) for the Subaru telescope: development of immersion gratings”, Diffractive Optics 2001, 12–13, 2001.Google Scholar

31. 

N. Ebizuka, S. Morita, H. Ohmori, Y. Yamagata, H. Kobayashi, Y. Hirahara, M. Wakaki and K. Kawaguchi “Development of immersion gratings for Subaru Telescope by means of ELID grinding method”, Advances in Abrasive Technology, III, eds. N. Yasunaga, J. Tamaki, K. Suzuki and T. Uematsu, The Soc. of Grinding Engineers Jpn, 149–154, 2000, ISBN 4-99000662-1-9.Google Scholar

© (2017) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Noboru Ebizuka, Noboru Ebizuka, Kiko Oka, Kiko Oka, Akiko Yamada, Akiko Yamada, Mami Ishikawa, Mami Ishikawa, Masako Kashiwagi, Masako Kashiwagi, Kashiko Kodate, Kashiko Kodate, Yasuhiro Hirahara, Yasuhiro Hirahara, Shuji Sato, Shuji Sato, Koji S. Kawabata, Koji S. Kawabata, Moriaki Wakaki, Moriaki Wakaki, Shin-ya Morita, Shin-ya Morita, Tomoyuki Simizu, Tomoyuki Simizu, Shaohui Yin, Shaohui Yin, Hitoshi Omori, Hitoshi Omori, Masanori Iye, Masanori Iye, } "Grism and immersion grating for space telescope", Proc. SPIE 10568, International Conference on Space Optics — ICSO 2004, 105681M (21 November 2017); doi: 10.1117/12.2308014; https://doi.org/10.1117/12.2308014
PROCEEDINGS
8 PAGES


SHARE
RELATED CONTENT

Million object spectrograph
Proceedings of SPIE (July 22 2008)
Grism development for EMIR
Proceedings of SPIE (January 29 2003)
Kilometer scale primary collector telescopy
Proceedings of SPIE (December 08 2004)

Back to Top