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Preliminary optical designs have been developed for the blue channel of the Low Resolution Imaging Spectrograph (LRIS) for the Keck Ten Meter Telescope. This paper discusses the configuration- driving factors and performance of the designs, as well as coating and fabrication issues.

The Low Resolution Imaging Spectrometer is designed for use at the Cassegrain focus of the Keck 10-m telescope. It provides the capability of acquiring low resolution (R equals 1000 to 5000) digital spectra, as well as 6 X 8 arc-minute moderately high spatial resolution (4.65 pixels/arc-second) direct images. Spectroscopy can be carried out with single slits which are 3 arc-minutes long. In addition punched multi-slits can also be employed which allow for the acquisition of at least forty spectra simultaneously. Since the instrument is designed to be as efficient as possible, it is a double spectrograph, with a dichroic splitting the blue and red light into separate optical paths after the collimator. Only the red side has been constructed thus far. With a 2048 by 2048 thinned Tektronix CCD as the detector the total efficiency of the red side at the peak of the grating blaze is predicted to be nearly 40%. Results of the commissioning observing runs will be described.

We are developing a submillimeter continuum camera for the Caltech Submillimeter Observatory (CSO) located on Mauna Kea. The camera will employ a monolithic Si bolometer array which was developed by Mosley et al. at the NASA Goddard Space Flight Center (GSFC). The camera will be cooled to a temperature of about 300 mK in a ^3He cryostat, and will operate primarily at wavelengths of 350 and 450 micrometers. We plan to use a bolometer array with 1 x 24 directly illuminated pixels, each pixel of dimension 1 x 2 mm^2, which is about half of the F/4 beam size at these wavelengths. Each pixel is 10 - 12 micrometers thick and is supported only by four thin Si legs formed by wet chemical etch. The pixels are doped n-type by phosphorus implantation, compensated by boron implantation. Signals from the bolometer pixels are first amplified by cryogenically cooled FETs. The signals are further amplified by room-temperature amplifiers and then separately digitized by 16 bit A/D converters with differential inputs. The outputs of the A/D converters are fed into a digital signal processing board via fiber-optic cables. The electronics and data acquisition system were designed by the Goddard group. We will report the status of this effort.

This article describes the design and construction of a CCD camera for the f/9 Cassegrain focus of the 200-inch (5m) Hale Telescope at Palomar Observatory. This instrument utilizes a set of 18-inch (0.45m) diameter lenses to change the Cassegrain focal ratio from f/16 to f/9, and the optical design prescription of these lenses is reported. For CCDs having 24 micrometers pixels, the f/9 focus gives a reciprocal plate scale of 9 pixels per arcsecond, which is well suited to precision photometry as well as future application to adaptive optics. In addition to the CCD and shutter, the instrument also incorporates an offset guider and an 8-position filter wheel.

We analyze the look and feel of each display and discuss its software design. Developed using the Motif Toolkit, each display runs on an X windows work station. In the area of look and feel, we discuss the pros and cons of graphically depicting the instrument light path. In the area of software design, we discuss Motif and Xlib programming techniques.