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Figures (25)

Fig. 1
Fig. 1

Two lasers function cooperatively in the ion-source portion of the mass spectrometer. The He–Ne laser, with its continuous beam, aids in detecting the presence of an aerosol particle. The pulsed Nd:YAG laser vaporizes the detected particle and ionizes its constituent molecules.

Fig. 2
Fig. 2

Directed by a microprocessor the laser fires the appropriate amount of pulses in correct locations to remove the necessary amount of material.

Fig. 3
Fig. 3

Laser-beam shield might consist of alternating layers of absorbing and reflecting material. When an absorbing layer and its reflective coating are vaporized, a new reflecting layer would be exposed.

Fig. 4
Fig. 4

This dual-carrier-lifetime laser is part of a transistor in which the emitter is the light source.

Fig. 5
Fig. 5

This video/data system merges digital data and video images. Approximately 345 Mbytes of digital data can be stored on a 2-h video cassette.

Fig. 6
Fig. 6

Data storage unit includes four 64-kbit dynamic RAMs with internal operations sequenced by a timing counter. The counter controls both the memory cycle and the read/write functions.

Fig. 7
Fig. 7

As it passes through a part, a beam of x rays or other radiation is attenuated and scattered. A computer records the variations in the beam as the part is rotated and constructs a cross section for display on a video monitor.

Fig. 8
Fig. 8

Two light-emitting diodes are stacked together to provide redundant line sources of light. This arrangement gives the required mechanical support to the delicate GaAs diode chips while permitting them to be closely spaced and adequately cooled by thermal conduction through the package.

Fig. 9
Fig. 9

Imaging device includes an n-type silicon substrate, a thermally grown silicon dioxide layer, and a sputtered film of piezoelectric ZnO. A ground electrode is deposited on the substrate. A transparent metallic biasing plate deposited on the piezoelectric layer is connected to ground through a variable voltage. The biasing plate enhances the acoustoelectric potential at the silicon dioxide interface, resulting in higher efficiency. A charge detecting diode is located in the silicon layer.

Fig. 10
Fig. 10

Improved grazing-incidence telescope, consisting of many concentric reflecting rings, is analogous to the multiple refracting rings of a Fresnel lens.

Fig. 11
Fig. 11

Designed for small size, this infrared imaging spectrometer uses a folded telescope and passes the input and output of its monochromator through a hole in the monochromator grating.

Fig. 12
Fig. 12

Cube-corner reflector returns a parallel, slightly displaced beam of light to an interrogating station. Pulses from the encoder/driver modulate the reflection, thereby providing a coded optical signal that can be used for target identification or navigation.

Fig. 13
Fig. 13

Baffle is produced by rotating this figure about the telescope axis. When rotated, the circular segment generates the surface of a torus, and the straight line generates the surface of a cone. This configuration is the simplest case of retroreflectors based on a multiple reflection between adjacent surfaces. For this configuration, the reflection properties depend on the parameters A and d and on the shape of the curved segment.

Fig. 14
Fig. 14

Ray reflections for a baffle angle of A = 29.50° are shown. To achieve less deviation in angle between the incident and reflected rays, the circular segment can be replaced with a parabolic, elliptic, or a more complicated segment. The straight line can similarly be replaced by a more suitable curve. (in centimeters)

Fig. 15
Fig. 15

This integrated chip combines a CCD with a fiber-optic waveguide. The chip comprises all the passive and active optical elements needed to connect with a fiber-optic sensing coil for a fiber gyroscope.

Fig. 16
Fig. 16

Backscatter and reflections are swept out of the CCD by rapid vertical transfers to eliminate detector swamping. The rapid vertical transfers are stopped just before the arrival of the return signal. Horizontal transfers sweep the signal out of the output register of the CCD to the following stage.

Fig. 17
Fig. 17

This dichroic reflector is designed for a resonant frequency of 8.415 GHz. The plate is 3.576 cm thick, with 2.273-cm diam holes spaced 2.388 cm center to center.

Fig. 18
Fig. 18

Modified dichroic reflector resembles the dichroic reflector of Fig. 21 except that the holes include flat side portions and round portions of slightly larger diameter.

Fig. 19
Fig. 19

Only two logic states are correct for the four conductors in lines A and B. These are shown at the top of the table. Any other combination of logic levels signifies an error in data processing or transmission. The circuit of the figure produces an output indicative of the correctness or of the type of error in the logic levels on the four conductors.

Fig. 20
Fig. 20

Signals A(a0, a1) and B(b0, b1) are fed to the new circuit. An error indication is obtained for any input combination other than (a0, a1; b0, b1) = (0, 1; 1, 0) or (1, 0; 0, 1).

Fig. 21
Fig. 21

Circuit includes operational amplifiers to change the level of the incoming signal to a value appropriate for the gates of the MESFETs. The slew rate of the operational amplifiers must be high enough to charge the 10-nF capacitors before the input signal itself does. Single-gate MESFETs are used as source followers. The microwave delay lines must be terminated with 50-Ω resistances to avoid reflections back to the outputs of the source followers.

Fig. 22
Fig. 22

Frequency of oscillation of this nand-gate-and-delay-line combination is determined by the delays in the gates and the propagation delays in the transmission lines. The gate delay, which is highly temperature-sensitive, should be small in comparison with the propagation delay.

Fig. 23
Fig. 23

This off-axis Schmidt imager and relay system has a 7°-by-7° field of view. The CCD at the image plane contains an array of 800 by 800 picture elements, each 15-μm square.

Fig. 24
Fig. 24

Infrared imager reads out accumulated charge on each of 128 indium antimonide photodiodes. Only one preamplifier is needed at the output of the video line.

Fig. 25
Fig. 25

This image of an infrared scene was generated by the photodiode array with the aid of a scanning mirror. Dark-current subtraction and computer processing would further improve image quality.

Equations (1)

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f = 1 2 ( τ g + τ d ) .

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