Internal reflection apparatus and method using a holographic optical element for a free space optical communication system

An apparatus, comprising:

• a first element through which to pass a light signal from a free space optical communication system;
• a second element having a first surface positioned adjacent to the first element and having a second surface;
• a holographic material having an interference pattern recorded thereon to receive the light signal passed through the first element, the interference pattern being structured to direct the light signal towards one of the surfaces of the second element to allow the light signal to propagate between the first and second surfaces of the second element via internal reflection;
• and
• an optical detector circuit coupled to the second element to receive the light signal that propagates between the first and second surfaces of the second element via internal reflection, wherein the optical detector circuit comprises an optical fiber that is positioned at an end surface of the second element different from the first and second surfaces.

An apparatus, comprising:

• a first element through which to pass a light signal from a free space optical communication system;
• a second element having a first surface positioned adjacent to the first element and having a second surface;
• a holographic material having an interference pattern recorded thereon to receive the light signal passed through the first element, the interference pattern being structured to direct the light signal towards one of the surfaces of the second element to allow the light signal to propagate between the first and second surfaces of the second element via internal reflection;
• and
• an optical detector circuit coupled to the second element to receive the light signal that propagates between the first and second surfaces of the second element via internal reflection wherein the optical detector circuit comprises a photodetector that is positioned near a surface of the second element different from the first and second surfaces.

An apparatus, comprising:

• a first element through which to pass a light signal from a free space optical communication system;
• a second element having a first surface positioned adjacent to the first element and having a second surface;
• a holographic material having an interference pattern recorded thereon to receive the light signal passed through the first element, the interference pattern being structured to direct the light signal towards one of the surfaces of the second element to allow the light signal to propagate between the first and second surfaces of the second element via internal reflection;
• a coupler prism positioned adjacent to the first surface of the second element to obtain a portion of the light signal that propagates between the first and second surfaces of the second element;
• and
• a position detector coupled to the coupler prism to provide orientation information based on the portion of the light signal obtained by the coupler prism.

An apparatus, comprising:

• a first element through which to pass a light signal from a free space optical communication system;
• a second element having a first surface positioned adjacent to the first element and having a second surface;
• a holographic material having an interference pattern recorded thereon to receive the light signal passed through the first element, the interference pattern being structured to direct the light signal towards one of the surfaces of the second element to allow the light signal to propagate between the first and second surfaces of the second element via internal reflection;
• an optical detector circuit coupled to the second element to receive the light signal that propagates between the first and second surfaces of the second element via internal reflection;
• and
• a coupler prism positioned adjacent to the first surface of the second element to obtain a portion of the light signal that propagates between the first and second surfaces of the second element, wherein a space between the coupler prism and the first surface is adjustable to control an amount of the light signal that reaches the optical detector circuit.

An apparatus, comprising:

• an element having a front surface and a back surface;
• a holographic optical element (HOE) disposed to angularly direct the light signal towards one of the surfaces of the element to allow the light signal to propagate between the front and back surfaces of the element via internal reflection;
• an optical detector circuit coupled to the element to receive, near a convergence point, the light signal that propagates between the front and back surfaces of the element;
• and
• a coupler prism positioned adjacent to the front surface of the element to obtain a portion of the light signal that propagates between the front and back surfaces of the element, wherein a space between the coupler prism and the front surface is adjustable to control an amount of the light signal that reaches the optical detector circuit.

An apparatus, comprising:

• an element having a front surface and a back surface;
• a holographic optical element (HOE) disposed to angularly direct the light signal towards one of the surfaces of the element to allow the light signal to propagate between the front and back surfaces of the element via internal reflection;
• a coupler prism positioned adjacent to the one of the surfaces of the element to obtain a portion of the light signal that propagates between the front and back surfaces of the element;
• and
• a position detector coupled to the coupler prism to provide orientation information based on the portion of the light signal obtained by the coupler prism.

A method, comprising:

• receiving a light signal from a free space optical communication system;
• and
• via use of a holographic optical element (HOE), angularly directing the light signal towards either a front surface or a back surface of an element to allow the light signal to propagate between the front and back surfaces via internal reflection;
• and
• controlling an amount of the light signal that reaches an optical detector circuit by changing a spacing between a coupler prism and a region of one of the surfaces of the element that internally reflect light signal.