5036767 : Optical window for laser-initiated explosive devices

ABSTRACT:   The optical window is useful in laser-initiated explosive devices. It includes a solid transparent block of high temperature-resistant material

such as glass, quartz, corundum, cubic zirconia or the like having two opposed light input and light output surfaces, one or both of which bear ablative mirror

coatings of metal or the like, preferably aluminum, silver or gold, which can be vaporized by a laser beam. Preferably, the coatings are covered by a protect-

ive ablative film which resists scratching or the like. Such may be, for example, silicon monoxide. The coatings reflect incident light so as to prevent inadver-

tent initiation of explosive situated behind or downstream of the window in an explosive device. Preferably, the block is cylindrical with a curved light-

focusing input surface which reduces the intensity which the laser beam trained through the window has to have in order to vaporize the mirror coatings and

set off the explosive. In one embodiment both the input and output surfaces of the block are coated with the mirrors, but the input surface mirror has a central

opening alignable with an optic fiber transmitting a laser beam, in order to facilitate passage of the beam into the block, while still providing protection

against stray radiation. When the mirror coating on the output end of the window vaporizes, its vaporization products facilitate and augment the detonation

of the exposive by the laser beam.

U.S. REFERENCES:

^* some details unavailable

9 CLAIMS: First Claim Shown (Show all claims)

What is claimed is:

• 1. An improved optical window for a laser-initiated explosive device, said window comprising, in combination:
• • a) a solid transparent block of high temperature resistant material, said block having two opposed light input and light output surfaces so that light can pass into, through and out of said block; and,
  • b) an ablative mirror coating on at least one of said opposed surfaces, said mirror coating reflecting incident light but ablatable by laser light to subsequently permit transmission of laser light through said opposed surfaces to an explosive initiator disposed adjacent said light output surface, said mirror coating being covered by a protective solid film of laser light-vaporizable material.

RELATED U.S. APPLICATIONS: none
FOREIGN REFERENCES: none
OTHER REFERENCES: none
PRIMARY/ASSISTANT EXAMINERS: Jordan; Charles T.;