The optical properties of gold

Abstract

The characteristic optical properties of gold, combined with its complete resistance to attack in any surroundings and its ability to be applied as very thin films, have led to a number of interesting and diverse applications in industry. The author, formerly Research Manager to the Metals Department of DEGUSSA, reviews these uses and the special properties upon which they are based. There are several technical applications of gold where its optical properties are of prime importance and can contribute to the solution of various problems. These include: The highly reflecting surfaces of satellites and space vehicles, of instruments on space capsules, and of space suits. Reflectors with glass or metal backing in heating or cryogenic temperature engineering. Plate glass windows in the motorcar and building industries for up to 50 per cent light transmission within certain frequency ranges and maximum reflection in other ranges. Diffraction screens for optical instruments for certain wavelength ranges to act as focusing lenses, and also highly reflecting graduated scales. Surface deposits on the solar energy distributors of solar cells to absorb radiated heat and to maintain the solar cells at optimum operating temperatures.

Gold films for the control and utilisation of radiant energy

“…The pure gold film has been prepared from an organometallic solution producing a conventional bright gold film. Although this film contains only 95 per cent gold-it contains among other constituents also a trace of rhodium to impart thermal stability-the measured reflectivity is in fair agreement with literature data for pure gold surfaces which have recently been reviewed by Loebich in this journal (17).…”

Electrochemical synthesis of nanostructured gold film for the study of carbohydrate–lectin interactions using localized surface plasmon resonance spectroscopy

“…The peak wavelength for NGF prepared by depositing Au at −1.2 V for a total duration of 90 s is 516.9 nm whereas the structure that was formed by depositing at this potential for 60 s shows a shoulder with an indistinct peak just near 500 nm. The reflectance spectrum of bare gold has a shoulder near 500 nm 63,64 similar to that observed in Figure 3B for gold electrodeposited at −1.2 V for 60 s. This suggested that these films are behaving similar to bulk gold and that a longer deposition time and a second step to more negative potentials is required to red shift the peak wavelength. All of the other preparations display peak wavelengths near 517 nm (see Table 1).…”

Interactive Diffraction from Biological Nanostructures

“…Though a gold film with thickness of only a few nanometres may transmit a fraction of incident light energy as suggested by Loebich [Loe72], for simplicity we treat it as an opaque layer. We simulate these geometric conditions in our renderer while ignoring minor keystone distortion between the screen and the camera plane as this does not affect our qualitative comparisons.…”