Abstract: A method and apparatus for sensing the wavelength of a laser beam using an optogalvano effect by atoms or molecules in plasma. Atoms or molecules in the plasma are irradiated with the laser beam. The impedance of the plasma at that time is sensed to sense whether the wavelength of the laser beam coincides with a predetermined absolute wavelength. The sensed result is used to control the wavelength of the laser beam.

Abstract: A reduced projection light source comprises a laser device for emitting laser light having a transverse mode of multimodes, and an etalon located between a chamber of the laser device and a total reflection mirror. The light source is used as an exposure light source for transfer printing an ultrafine pattern on a semiconductor wafer.

Abstract: Specification of an etalon included in a multimode, narrow-band oscillation excimer laster used as a light source for light exposure in photolithography are set to satisfy a relation S.lambda.W.lambda.R.lambda. (u,v)d.lambda..gtoreq..alpha., where .alpha. is an optical transfer function necessary for light exposure of resist according to a reticle pattern, R.lambda.(u,v) is an optical transfer function of monochromatic light for an illuminating system and a reduced-projection lens, W.lambda. is a weight which is applied to a waveform of a power spectrum in an oscillation laser beam at a wavelength .lambda.. Further, an inclination angle .lambda. of the etalon in its normal direction with respect to an optical axis when the etalon is provided between the chamber and rear mirror is set to satisfy a relation .theta.>tan.sup.

Abstract: An MOS type read-only memory device having a reduced power consumption has a clock signal generator circuit for generating a pair of positive and negative clock signals by detecting a change of an address signal in the ROM having MOS transistors used as a load and connected to bit lines, a tri-state circuit including an input, a control signal input, and an ouput; the tri-state circuit has its output impedance made higher due to a clock signal supplied to the control signal input. The device also has a switching circuit for keeping the MOS transistors used as a load in their active state based on a clock signal. The inputs and outputs of the tri-state circuit are each connected to the bit lines and gates of the MOS transistors used as a load. The switching circuit is connected to the gate side of the MOS transistors used as a load.

Abstract: The present invention is a cant angle sensor assembly which senses the amount of tilt of an object in the longitudinal, transverse and oblique directions and which effectively exhibits a damper action in all directions by a single magnetic damper means.