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We have developed an optical and near-infrared instrument HONIR (Hiroshima Optical and Near-InfraRed camera) with imaging, spectroscopy, and polarimetry capabilities in two (one optical and one near-infrared) bands simultaneously. Imaging capability with a field of view of 10 arcmin by 10 arcmin has been available since 2011, as reported in the previous SPIE conference. In addition, spectroscopic and polarimetric optical components (grisms, an Wollaston prism, a half-wave plate, and focal masks) were installed in the instrument, which enabled us to perform spectroscopy and linear polarization measurement by imaging polarimetry and spectro-polarimetry. Spectral resolution of R = λ/(triangle)λ ~ 440 - 800 is achieved in spectroscopy using a slit mask with an 1".3 width. In polarimetry, instrumental polarization is less than ~0.05 % with stability of better than ~0.05 %, which is sufficiently small to achieve an aimed accuracy of polarization measurement of ~0.1 % at primal observing wavelengths.

The Thirty Meter Telescope is a next-generation optical/infrared telescope to be constructed on Mauna Kea, Hawaii toward the end of this decade, as an international project. Its 30 m primary mirror consists of 492 off-axis aspheric segmented mirrors. High volume production of hundreds of segments has started in 2013 based on the contract between National Astronomical Observatory of Japan and Canon Inc.. This paper describes the achievements of the high volume production trials. The Stressed Mirror Figuring technique which is established by Keck Telescope engineers is arranged and adopted. To measure the segment surface figure, a novel stitching algorithm is evaluated by experiment. The integration procedure is checked with prototype segment.

We developed a new readout system for the near-infrared detector VIRGO-2K (2kx2k HgCdTe array) installed in the optical-infrared simultaneous camera, HONIR, for the 1.5 m Kanata telescope at Higashi-Hiroshima observatory. The main goal of this development is to read out one frame within ~ 1 second through 16 output readout mode of the detector, in order to reduce the overhead time per exposure. The system is based on a CCD controller, Kiso Array Controller (KAC). We redesigned the analog part of KAC to fit VIRGO-2K. We employed a fully differential input circuit and a third order Bessel low-pass filter for noise reduction and a constant current system to improve the linearity of the detector. We set the cutoff frequency of the Bessel low-pass filter at the readout clock rate (120 kHz). We also set the constant current at 200 μA according to the data sheet of VIRGO-2K. We tested the new readout system at room temperature and confirmed that the low-pass filter works well as designed. The fluctuation of the current level of the constant current system is less than 2% for the typical output voltage range of VIRGO-2K (3.2-4.4 V). We measured the readout noise caused by the new readout system (connected to cooled multiplexer) and found that it is 30-40 μV rms, being comparable to or slightly higher than the typical readout noise of VIRGO-2K, ∼ 37 μV rms.

A mid-infrared (MIR) imager and spectrometer is being investigated for possible construction in the early operation of the Thirty Meter Telescope (TMT). Combined with the MIR adaptive optics (AO) system (MIRAO), the instrument will afford ~15 times higher sensitivity and ~4 times better spatial resolution (0.07”) at 10μm compared to 8m-class telescopes. Additionally, through exploiting the large collection area of the TMT, the high-dispersion spectroscopy mode will be unrivaled by other ground- and space-based facilities. These combined capabilities offer the possibility for breakthrough science, as well as ‘workhorse’ observing modes of imaging and low/moderate spectral resolution. In this paper we summarize the primary science drivers that are guiding the instrument design.

We have developed an optical-infrared instrument HONIR (Hiroshima Optical and Near-InfraRed camera) to be attached to the 1.5-m Kanata telescope at Higashi-Hiroshima Observatory, Hiroshima University. HONIR is a three color (one optical and two near-infrared bands among 0.5–2.4 µm) simultaneous imager and spectrograph with a polarimetry function. The field of view of the imaging mode is 10 arcmin square with a spatial sampling of 0".29. Among the planned multipurpose functions, a two color (0.5–1.0 µm and 1.15–2.40 µm) simultaneous imaging function has been installed and operated so far. The remaining functions, spectroscopy and polarimetry, and the second near-infrared band arm, are under development and will be installed in the near future.

The Thirty Meter Telescope (TMT) is a next-generation optical/infrared telescope to be constructed on Mauna Kea, Hawaii toward the end of this decade, as an international project. Its 30 m primary mirror consists of 492 off-axis aspheric segmented mirrors. This paper describes the progress of the test fabrication of an outermost mirror segment for the TMT as a joint R&D program between National Astronomical Observatory and Canon. A zero-expansion glass CLEARCERAM™ blank was polished by a computer-controlled small-tool polishing machine (CSSP, Canon) and its surface shape was measured by a touch-probe measuring machine(A-Ruler, Canon). Residuals of lower Zernike terms of the surface shape were 11 nmRMS, clearing the original specifications based on the structure function. There remains, however, a need to fulfill latest revised specifications. Possible solutions to improve and achieve the new specifications and a plan for revising the process for mass production are also described.

We are developing an integral field unit (IFU) with an image slicer for the existing optical imaging spectrograph, Faint Object Camera And Spectrograph (FOCAS), on the Subaru Telescope. Basic optical design has already finished. The slice width is 0.4 arcsec, slice number is 24, and field of view is 13.5x 9.6 arcsec. Sky spectra separated by about 3 arcmin from an object field can be simultaneously obtained, which allows us precise background subtraction. The IFU will be installed as a mask plate and set by the mask exchanger mechanism of FOCAS. Slice mirrors, pupil mirrors and slit mirrors are all made of glass, and their mirror surfaces are fabricated by polishing. Multilayer dielectric reflective coating with high reflectivity (< 98%) is made on each mirror surface. Slicer IFU consists of many mirrors which need to be arraigned with high accuracy. For such alignment, we will make alignment jigs and mirror holders made with high accuracy. Some pupil mirrors need off-axis ellipsoidal surfaces to reduce aberration. We are conducting some prototyping works including slice mirrors, an off-axis ellipsoidal surface, alignment jigs and a mirror support. In this paper, we will introduce our project and show those prototyping works.

We evaluated depth of subsurface damage on a ground surface of the ultra low expansion glass-ceramics CLEARCERAMR®-Z HS (CC-Z HS) by Ohara Inc., which is one of the candidates for material for segmented mirrors of the Thirty Meter Telescope. We made polishing spots of Magnetorheological Finishing on the ground surface of CC-Z HS and measured exposed subsurface damage features on the spot surface. We also studied on hydrofluoric acid etching of the CC-Z HS ground surface, which is expected to be an effective method to remove a subsurface damage layer compared with time-consuming polishing. We etched small ground surfaces of CC-Z HS and evaluated its uniformity.

A mid-infrared imager and spectrometer is under consideration for construction in the first decade of the Thirty- Meter Telescope (TMT) operation (see the companion paper by Okamoto). MIRES, a mid-infrared high-spectral resolution optimized instrument, was previously proposed to provide these capabilities to the TMT community. We have revised the design in order to provide an improved optical design for the high-spectral resolution mode with R=120,000, improved imaging with sky chopping, low-spectral resolution mode with an integral field spectrograph, and polarimetry. In this paper we describe the optical design concepts currently under consideration.

A mid-infrared (MIR) imager and spectrometer is being investigated for possible consideration for construction in the early operation of the Thirty Meter Telescope (TMT). Combined with adaptive optics for the MIR, the instrument will afford 15 times higher sensitivity (0.1mJy as 5 sigma detection in 1hour integration in the N-band imaging) and 4 times better spatial resolution (0.08") at 10μm compared to 8m-class telescopes. In addition, its large light-gathering power allows high-dispersion spectroscopy in the MIR that will be unrivaled by any other facility. We, a collaborating team of Japanese and US MIR astronomers, have carefully considered the science drivers for the TMT MIR instrument. Such an instrument would offer both broad and potentially transformative science. Furthering the science cases for the MIRES1, where high-dispersion spectroscopy was emphasized, we discuss additional capabilities for the instrument drawn from the enlarged science cases. The science cases include broader areas of astronomical fields: star and planet formation, solar system bodies, evolved stars, interstellar medium (ISM), extragalaxies, and cosmology. Based on these science drivers, essential instrument capabilities and key enhancement are discussed (see the companion paper Tokunaga et al. 20102): specifically imaging, lowand high-spectral resolution modes, integral field spectroscopy, and polarimetry.

For prompt optical polarimetry of gamma-ray burst (GRB) afterglow, we require wide-field imaging polarimeter which can produce both Stokes Q and U parameters from only a single exposure, as well as quickly-moving telescope and enclosure system. HOWPol is an optical imaging polarimeter which provides four linearly polarized images at position angles of 0°, 45°, 90° and 135°, i.e., Stokes I, Q, U, simultaneously. The key device is the wedged double Wollaston prism described by Oliva (1997)1 and Pernechele et al. (2003).2 The images are focused on two 2k×4k fully depleted CCDs. We report the design and development of the optical devices of HOWPol, which will be mounted to the 1.5-m Kanata telescope at Hiroshima University and stand by the GRB alert.

COMICS is an observatory and mid-infrared instrument for the 8.2 m Subaru Telescope. It is designed for imaging and spectroscopic observations in the N- (8-13 micron) and Q-bands (16-25 micron) atmospheric windows. The design and very preliminary performances at the first light observations in December 1999 were reported at the SPIE meeting in 2000. We describe here the improved performances of COMICS and capability of high spectral resolution spectrocopy which became available from December 2001. We will also briefly report preliminary scientific results.

We developed a new data acquisition device for COMICS, a mid infrared instrument of the Subaru telescope. The new device was installed in place of our previous data acquisition device with a lower data transfer speed. The new device is 32 bit PCI bus and PC Linux based and provides bus-master DMA transfer function. It consists of a clock pattern generator, frame memories, and an image co-adder. In order to achieve high operational efficiency for mid infrared instruments, the data handling speed is essential as well as the speed of A/D converter. The data transfer to the hard disk drive on the PC is made during acquiring the data at the rate higher than the data generation rate. As a result, we succeeded to reduce the dead time due to the data transfer procedure from 60 sec to less than 1 sec for 200 frames (64M bytes). Furthermore by replacing the host computer by a higher performance PC, the observation efficiency of COMICS was improved from 44% to 74% in the imaging mode. This PCI based data acquisition device can also be applied to the other instruments that have fast data rates.

The Subaru Telescope has seven first generation optical and infrared instruments now being handed-over from the instrument teams to the observatory and being offered for its open use. We describe brief history of the telescope project and overview of the instrumentation program. Brief status of the Individual instruments is given separately. Exchanging focal plane and instruments is important for such multi-purpose telescope and the effectiveness of the system with the Subaru Telescope is discussed. Finally, current challenges of the program and future plans are summarized.

In this paper, we present the design and test performance of the COMICS, the mid-IR instrument for the 8.2 m Subaru Telescope at Mauna Kea. The instrument has both imaging and long slit grating spectroscopy capabilities in the 8-26 micrometers wavelength range. In the camera section, there are selectable three sets of lens assembly, one for the 10 micrometers imaging, another for the 20 micrometers imaging, and the other for the 10 micrometers pupil imaging. This camera section has an SBRC 320 X 240 Si:As IBC array and serves as a slit viewer and as a camera pixel scale of 0.130 arcsec. The spectrograph section is designed to have fiber SBRC 320 X 240 Si:As IBC arrays. Five arrays will cover 8-13 micrometers wavelength range in two positions of the grating with resolving power around 2500. So far, two arrays are installed for the spectrograph section and full spectral region is covered with tilting the grating. Selectable four sets of gratings provide spectral resolution ranging from 250 to 10000 in the N band and around 2500 in the Q band.

We have developed the mid-IR Camera and Spectrometer (MICS), which optimized for ground based observations in the N-band atmospheric window. The MICS has two observing capabilities, imaging and long slit low-resolution spectroscopy. The major characteristics of the MICS are nearly diffraction-limited performance, both in imaging and in spectroscopy and the capability to take a spectrum of the whole N-band range with a spectral resolving power of 100 under one exposure. The MICS employs a 2D array of 128 by 128 Si:As BIB detector, an aberration-corrected concave grating, and a high-speed read out system of a compact design with high sensitivity. In mid-IR observations form the ground, there is a large background radiation from the telescope and the sky. The fluctuation of the background radiation is not well understood so far. We measured the sky fluctuation in the N- band region with the MICS on the UKIRT. These measurements have revealed that (1) the sky noise was dominant below 0.5 Hz when the sky condition was good, and (2) the sky noise has strong excess at the positions of atmospheric water vapor lines than those without water vapor lines. In this paper, we describe the design of the MICS, including optics, cryogenics, and electronics, and its performance when used on the UKIRT. We also discuss sky noise measured by the MICS in the N-band region.