Virtually imaged phased array (VIPA) having air between reflecting surfaces

An apparatus receiving a wavelength division multiplexed light focused into a line and comprising at least two carriers, the apparatus producing a spatially distinguishable output light for each carrier, the apparatus comprising:

• first and second surfaces separated from each other with air in between, the second surface having a reflectivity which allows a portion of light incident thereon to be transmitted therethrough, the first and second surfaces positioned so that the wavelength division multiplexed light travels from the line to be reflected a plurality of times between the first and second surfaces through the air to cause a plurality of lights to be transmitted through the second surface, the plurality of transmitted lights interfering with each other to produce a respective output light for each carrier of the wavelength division multiplexed light,
• wherein each carrier is at a respective wavelength within a continuous range of wavelengths and the output light formed for a respective carrier is spatially distinguishable from an output light formed for a carrier having any other wavelength within the continuous range of wavelengths.

An apparatus comprising:

• first and second surfaces separated from each other with air in between, the second surface having a reflectivity which causes a portion of light incident thereon to be transmitted therethrough, wherein
• an input light at a respective wavelength is focused into a line, and
• the first and second surfaces are positioned so that the input light radiates from the line to be reflected a plurality of times between the first and second surfaces through the air and thereby cause a plurality of lights to be transmitted through the second surface, the plurality of transmitted lights interfering with each other to produce an output light which is spatially distinguishable from an output light produced for an input light at a different wavelength.

An apparatus comprising:

• first and second surfaces separated from each other with air in between, the second surface having a reflectivity which causes a portion of light incident thereon to be transmitted therethrough, wherein
• an input light at a respective wavelength is focused into a line, and
• the first and second surfaces are positioned so that the input light radiates from the line to be reflected a plurality of times between the first and second surfaces through the air and thereby cause a plurality of lights to be transmitted through the second surface, each transmitted light interfering with each of the other transmitted lights to produce an output light which is spatially distinguishable from an output light produced for an input light at a different wavelength.

An apparatus receiving a line focused input light having a respective wavelength within a continuous range of wavelengths, the apparatus comprising:

• first and second surfaces spaced apart from each other with air in between;
• and
• means for causing multiple reflection of the line focused input light between the first and second surfaces through the air to produce self-interference that forms an output light, wherein the output light is spatially distinguishable from an output light formed for an input light having any other wavelength within the continuous range of wavelengths.

An apparatus receiving an input light at a respective wavelength and focused into a line, the apparatus comprising:

• first and second surfaces spaced apart from each other with air in between;
• and
• means for causing the input light to radiate from the line to be reflected a plurality of times between the first and second surfaces through the air and thereby cause a plurality of lights to be transmitted through the second surface, and for causing the transmitted lights to interfere with each other to produce an output light which is spatially distinguishable from an output light produced for an input light at a different wavelength .