C haptEr 9 design Environments and systems
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tive of imparting needed or desired light behaviors. Many needed
light-control qualities can be obtained from imparting some type
of orderly or aligned structure at the submicron or nanoscale to
a thin film, which in turn orders light waves in particular ways or
affects phenomena such as refraction. This ordering can be accomplished in many ways by use of the synthesis techniques described
in Chapter 8, including, for example, electron-beam evaporation
techniques that cause linear structures to grow on substrates, various
kinds of processes for thin crystalline films that are self-assembling
customized crystals in solution and self-aligning when deposited,
and nanomanufacturing techniques for making nanoscale perforations or grooves. The need for multiple layers is common.
Many of the current applications already in use and that will be
described shortly already use multiple layers and exploit the unique
optical properties of nanoparticles to a greater or lesser degree.
Varying particle types, size, and layer structures and the compositions of various layers offer increased control of different kinds of
important optical behaviors and related reflection, absorption, and
transmission characteristics as well as creating opportunities for
some truly new products.
antireflection, transmission, and
Contrast Enhancement
The eyes of moths are known to have both reduced reflections and
enhanced seeing ability, particularly in darkened environments.
The reduced reflections prevent predators from easily seeing them.
Moth eyes have been found to be covered with thin nanostructured
films. Many coatings and films are now available that exhibit similar
antireflective and light enhancement qualities. The use of antireflective coatings typically serves one of the following primary purposes:
to directly reduce reflections (including cutting down glare produced
by reflections), to increase light transmission through a surface, or
to increase contrast. These coatings are widely used in architectural
applications, particularly with glass in relation to visible and ultraviolet light; in many product design applications such as computer
screens; and in consumer products such as tinted eyeglasses. Antireflective coatings in common use normally consist of multiple layers
of transparent thin films, with different layers having varying refractive indices, as we’ll discuss shortly. Characteristics and thicknesses
are selected to produce destructive interferences for reflected light
waves and destructive interferences for transmitted waves. Normally
these behaviors vary with the wavelength of the impinging light
348
tive of imparting needed or desired light behaviors. Many needed
light-control qualities can be obtained from imparting some type
of orderly or aligned structure at the submicron or nanoscale to
a thin film, which in turn orders light waves in particular ways or
affects phenomena such as refraction. This ordering can be accomplished in many ways by use of the synthesis techniques described
in Chapter 8, including, for example, electron-beam evaporation
techniques that cause linear structures to grow on substrates, various
kinds of processes for thin crystalline films that are self-assembling
customized crystals in solution and self-aligning when deposited,
and nanomanufacturing techniques for making nanoscale perforations or grooves. The need for multiple layers is common.
Many of the current applications already in use and that will be
described shortly already use multiple layers and exploit the unique
optical properties of nanoparticles to a greater or lesser degree.
Varying particle types, size, and layer structures and the compositions of various layers offer increased control of different kinds of
important optical behaviors and related reflection, absorption, and
transmission characteristics as well as creating opportunities for
some truly new products.
antireflection, transmission, and
Contrast Enhancement
The eyes of moths are known to have both reduced reflections and
enhanced seeing ability, particularly in darkened environments.
The reduced reflections prevent predators from easily seeing them.
Moth eyes have been found to be covered with thin nanostructured
films. Many coatings and films are now available that exhibit similar
antireflective and light enhancement qualities. The use of antireflective coatings typically serves one of the following primary purposes:
to directly reduce reflections (including cutting down glare produced
by reflections), to increase light transmission through a surface, or
to increase contrast. These coatings are widely used in architectural
applications, particularly with glass in relation to visible and ultraviolet light; in many product design applications such as computer
screens; and in consumer products such as tinted eyeglasses. Antireflective coatings in common use normally consist of multiple layers
of transparent thin films, with different layers having varying refractive indices, as we’ll discuss shortly. Characteristics and thicknesses
are selected to produce destructive interferences for reflected light
waves and destructive interferences for transmitted waves. Normally
these behaviors vary with the wavelength of the impinging light