Kerr cells

V at 100 MC/sec compared with 10 kV in Kerr cells) and they transmit over a wide spectral range (2500-12000 A). When designed as travelling wave modulators, they can be used even up to micro-wave modulation frequencies... 

Studies were made of the detonation with hemispherical, ellipsoidal, and conical liners and a theory was developed which appeared to give a plausible explanation of the optimum shapes of liners. It was discovered during these studies, that highspeed rotation decreased very markedly the cavity effect, and that consequently, spin-stabilized projectiles were ill-adapted to cavity charges. Towards the end of 1943, the spreading of the jet, due to rotation, was confirmed photographically by the Kerr-cell camera... 

No 5, p 658(1951) (On the diminution of brisance of hollow charges caused by rotation) 33) E.M. Pugh et al, JApplPhys 22, 487-93(1951) (Application of Kerr-Cell to photographing of metal jets squirted from lined conical HE s charges) 34) D.C. 

Frequently it is as necessary to cut off the illumination as quickly and precisely as it is to turn it on. Internal electro-shuttering, such as accomplished with the Faraday and Kerr cells, can be synchronized with the camera and event exactly as needed (Ref 17). However, as mentioned1 above, cameras such as the Beckman/ Whitley framing camera as well as most continuously writing streak cameras, run the risk of incurring double exposures (Ref 13). 

Kerr Cell. See under Cameras, High-Speed Photographic in Vol 2, p C15-L... 

Until recently a general drawback of this passive Q-switching scheme was the difficulty of obtaining an exact synchronization of the giant pulse with other events in more complex experiments. This difficulty does not exist with active Q-switching in which an electro-optic device, e.g. a Kerr-cell or Pockels-cell, is used instead of a dye cell, and one is able to determine exactly the time at which... 

Clark (Ref 5) described flash photography applied to ordnance problems. Quinn et al (Ref 6) described Kerr- cell camera and flash illumination unit for ballistic photography. Sultanoff (Ref 7) described a 100 million frame per second camera. Courtney- Pratt (Ref 8) described fast multiple plate photography. Aspden described electronic flash photography in his book (Ref 9)... 

Randomly distributed dipolar molecules form an isotropic medium characterized by a single refractive index n. When these molecules are more or less aligned in an electric field the medium becomes anisotropic and its optical properties must be described by two refractive indices. The Kerr cell consists of a glass vessel fitted with two parallel optical windows and two metal electrodes (Figure 2.11). The cell contains a liquid or a gas (solids can also be used) when an electric field exists between the electrodes the phase difference between the electric vectors is proportional to the square of the field and to the value of the electrical Kerr constant of the dielectric... 

There is another way to obtain giant laser pulses of a few ns duration, known as active Q-switching. The shutter is an electro-optical cell which is triggered at some preset time after the pump flash. These electro-optical shutters are Kerr cells or Pockels cells. 

One of the first cameras applying Kerr-cell to study ballistic problems was designed by Deutsch (ca 1930). His app was modified in 1932 by Cranz, Kutrerer Schardin to become known as "Kerreffekt-Chronograph (Ref 2,p 165). Kerr-cell camera proved to be useful for photographing highly sei.. umxrous effects, such as detonations... 

The application of an external field onto many materials will induce optical anisotropy. If the applied field oscillates, a time-dependent modulation of the polarization of the light transmitted by the device will result. Modulators of this sort include photoelastic modulators (PEM) [30,31], Faraday cells [32], Kerr cells [32], and Pockel cells. 

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