Albert A. Bouwers (1893–1972) was a

Dutch Dutch or Nederlands commonly refers to: * Something of, from, or related to the Netherlands ** Dutch people as an ethnic group () ** Dutch nationality law, history and regulations of Dutch citizenship () ** Dutch language () * In specific terms, i ...

optical engineer Optics is the branch of physics that studies the behaviour and properties of light, including its interactions with matter and the construction of instruments that use or detect it. Optics usually describes the behaviour of visible, ultravio ...

.Ian Ridpath, "Bouwers telescope", ''A Dictionary of Astronomy'', 199
first sentence of article
/ref> He is known for developing and working with

X-rays An X-ray (also known in many languages as Röntgen radiation) is a form of high-energy electromagnetic radiation with a wavelength shorter than those of ultraviolet rays and longer than those of gamma rays. Roughly, X-rays have a wavelength ran ...

and various optical technologies as a high-level researcher at

Philips Koninklijke Philips N.V. (), simply branded Philips, is a Dutch multinational health technology company that was founded in Eindhoven in 1891. Since 1997, its world headquarters have been situated in Amsterdam, though the Benelux headquarter ...

research labs. He is lesser known for patenting in 1941 a

catadioptric A catadioptric optical system is one where refraction and reflection are combined in an optical system, usually via lenses ( dioptrics) and curved mirrors ( catoptrics). Catadioptric combinations are used in focusing systems such as searchlig ...

meniscus telescope design similar to but slightly predating the

Maksutov telescope 250px, A 150mm aperture Maksutov–Cassegrain 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 sur ...

.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 Dalen (Dutch Low Saxon: ''Daoln'') is a village and a former municipality in the northeastern Netherlands, in the province of Drenthe. Since 1998, Dalen has been part of the municipality of Coevorden. The village was first mentioned in the 12th ...

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; , formerly ''Rijksuniversiteit Utrecht'') is a public university, public research university in Utrecht, Netherlands. Established , it is one of the oldest universities in the Netherlands. In 2023, it had an enrollment of ...

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) or 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 ...

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

Time Time is the continuous progression of existence that occurs in an apparently irreversible process, irreversible succession from the past, through the present, and into the future. It is a component quantity of various measurements used to sequ ...

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

cesium Caesium (IUPAC spelling; also spelled cesium in American English) is a chemical element; it has 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 ...

and

antimony Antimony is a chemical element; it has chemical symbol, symbol Sb () and atomic number 51. A lustrous grey metal or metalloid, it is found in nature mainly as the sulfide mineral stibnite (). Antimony compounds have been known since ancient t ...

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 a surname. Notable people with the surname include: * Barney Olde (1882–1932), Australian politician * Erika Olde, Canadian film producer, financier and billionaire heiress * Hans Olde (1855–1917), German painter and art school administ ...

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 (patented February 1941) similar to, and slightly predating,

Russian Russian(s) may refer to: *Russians (), an ethnic group of the East Slavic peoples, primarily living in Russia and neighboring countries *A citizen of Russia *Russian language, the most widely spoken of the Slavic languages *''The Russians'', a b ...

optician

Dmitri Dmitrievich Maksutov Dmitry Dmitrievich Maksutov (; – 12 August 1964) was a Soviet Union, Soviet Optical engineering, optical engineer and amateur astronomer. He is best known as the inventor of the Maksutov telescope. Biography Dmitry Dmitriyevich Maksutov was b ...

'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 Bernhard Woldemar Schmidt (, Naissaar, Nargen, Estonia – 1 December 1935, Hamburg) was an Estonian optician. In 1930 he invented the Schmidt camera, Schmidt telescope, which corrected for the optical errors of spherical aberration, coma, and a ...

'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 ...

") had the spherical mirror and spherical "

meniscus corrector shell 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 ...

" 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, the aperture of an optical system (including a system consisting of a single lens) is the hole or opening that primarily limits light propagated through the system. More specifically, the entrance pupil as the front side image of ...

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, color aberration, color fringing, or purple fringing, is a failure of a lens to focus all colors to the same point. It is caused by dispersion: the refractive index of the ...

and was only suitable as a monochromatic astronomical

astrographic camera An astrograph (or astrographic camera) is a telescope designed for the sole purpose of astrophotography. Astrographs are mostly used in wide-field astronomical surveys of the sky and for detection of objects such as asteroids, meteors, and ...

working at a single

wavelength of light In physics and mathematics, wavelength or spatial period of a wave or periodic function is the distance over which the wave's shape repeats. In other words, it is the distance between consecutive corresponding points of the same ''phase'' on t ...

. Bouwers came up with a later design that used a cemented

doublet Doublet is a word derived from the Latin ''duplus'', "twofold, twice as much",