Albert A. Bouwers (1893–1972) was a Dutch optical engineer.Ian Ridpath, "Bouwers telescope", ''A Dictionary of Astronomy'', 199
first sentence of article
/ref> He is known for developing and working with

X-rays X-rays (or rarely, ''X-radiation'') are a form of high-energy electromagnetic radiation. In many languages, it is referred to as Röntgen radiation, after the German scientist Wilhelm Conrad Röntgen, who discovered it in 1895 and named it ' ...

and various optical technologies as a high-level researcher at

Philips Koninklijke Philips N.V. (), commonly shortened to Philips, is a Dutch multinational conglomerate corporation that was founded in Eindhoven in 1891. Since 1997, it has been mostly headquartered in Amsterdam, though the Benelux headquarters is ...

research labs. He is lesser known for patenting in 1941 a catadioptric meniscus telescope design similar to but slightly predating the

Maksutov telescope The Maksutov (also called a "Mak") is a catadioptric telescope design that combines a spherical mirror with a weakly negative meniscus lens in a design that takes advantage of all the surfaces being nearly "spherically symmetrical". The negative ...

.Evolution of the Maksutov design
/ref>Reflecting Telescope Optics: Basic design theory and its historical development, By Ray N. Wilson page 150
/ref>

Biography

Bouwers was born in the town of Dalen in the Netherlands in 1893.Reflecting Telescope Optics, by Ray N. Wilson, page 498
Google Books, pg 498
/ref> He obtained his Ph.D. from

Utrecht University Utrecht University (UU; nl, Universiteit Utrecht, formerly ''Rijksuniversiteit Utrecht'') is a public research university in Utrecht, Netherlands. Established , it is one of the oldest universities in the Netherlands. In 2018, it had an enrollm ...

in 1924, with a dissertation entitled in Dutch ''Over het meten der intensiteit van Röntgenstralen''. He was also the director of the Philips Laboratory's X-ray department. Bouwers developed a

night vision device A night-vision device (NVD), also known as a night optical/observation device (NOD), night-vision goggle (NVG), is an optoelectronic device that allows visualization of images in low levels of light, improving the user's night vision. The de ...

for viewing in low light conditions, called the "night eye"."The View in the Dark"
''

Time Time is the continued sequence of existence and events that occurs in an apparently irreversible succession from the past, through the present, into the future. It is a component quantity of various measurements used to sequence events, t ...

''. June 21, 1963. Archived fro
the original
October 17, 2007. The design used a photosensitive layer of

cesium Caesium ( IUPAC spelling) (or cesium in American English) is a chemical element with the symbol Cs and atomic number 55. It is a soft, silvery-golden alkali metal with a melting point of , which makes it one of only five elemental metals that ...

and

antimony Antimony is a chemical element with the symbol Sb (from la, stibium) and atomic number 51. A lustrous gray metalloid, it is found in nature mainly as the sulfide mineral stibnite (Sb2S3). Antimony compounds have been known since ancient ti ...

in a cathode-ray tube, to brighten images by over 1,000 times. Unlike active infrared systems, it did not require an infrared flashlight. The design was initially produced by

Olde Delft Optical Company Olde is the surname of: * Barney Olde (1882–1932), Australian politician * Erika Olde, Canadian film producer, financier and billionaire heiress * Hans Olde (1855–1917), German painter and art school administrator * Margareth Olde (born 2000), ...

in the Netherlands.

Bouwers meniscus telescope

In August 1940''The History of the Telescope'' By Henry C. King, page 360
google books
/ref> Albert Bouwers built a prototype for a design for a wide field concentric

meniscus telescope A meniscus corrector is a negative meniscus lens that is used to correct spherical aberration in image-forming optical systems such as catadioptric telescopes. It works by having the equal but opposite spherical aberration of the objective it i ...

(patented February 1941) similar to, and slightly predating, Russian optician Dmitri Dmitrievich Maksutov's 1941

. War time secrecy kept Bouwers and Maksutov from knowing about each other's designs and Bouwers' design was not published until after World War II. Bouwers original design (based on an earlier catadioptric telescope, Bernhard Schmidt's "

Schmidt camera A Schmidt camera, also referred to as the Schmidt telescope, is a catadioptric astrophotographic telescope designed to provide wide fields of view with limited aberrations. The design was invented by Bernhard Schmidt in 1930. Some notable e ...

") had the spherical mirror and spherical " meniscus corrector shell" all with a common radius of curvature (a concentric or monocentric design) resulting in a perfectly spherical symmetry of the whole optical device. Like the Schmidt camera, the meniscus telescope has the

aperture stop In optics, an aperture is a hole or an opening through which light travels. More specifically, the aperture and focal length of an optical system determine the cone angle of a bundle of rays that come to a focus in the image plane. An op ...

coincide with the center of curvature. It also shares the Schmidt's curved image plane. The design has an ultrawide field of view with no spherical aberration but does not correct

chromatic aberration In optics, chromatic aberration (CA), also called chromatic distortion and spherochromatism, is a failure of a lens to focus all colors to the same point. It is caused by dispersion: the refractive index of the lens elements varies with the ...

and was only suitable as a monochromatic astronomical astrographic camera working at a single wavelength of light. Bouwers came up with a later design that used a cemented doublet to form the meniscus corrector shell to correct chromatic aberration.D. J. Schroeder (2000)
''Astronomical Optics''
page 202.

Biography

Bouwers meniscus telescope

References

Further reading