Method and apparatus for implementing a multi-channel tunable filter

A method for using a multi-channel tunable filter comprising:

• moving an optical read-head in a first vertical direction with respect to a face of a three-dimensional filter material comprising one or more gratings recorded onto said three-dimensional filter material wherein each of said gratings is configured to reflect a given wavelength of a light wave and wherein each of said gratings covers a vertical portion of said three-dimensional filter material;
• moving said optical read-head in a horizontal direction with respect to said face of said three-dimensional filter material;
• and
• moving said optical read-head in a second vertical direction with respect to said face of said three-dimensional filter material.

A method for recording gratings comprising:

• reflecting a first beam off a first mirror stack;
• reflecting a second beam off a second mirror stack;
• and
• producing an interference between reflection of said first beam and reflection of said second
• beam wherein said interference etches in a recording material to form said gratings.

A method for recording gratings comprising:

• using a multiple channel phase mask to direct a first order beam of said phase mask at a recording material;
• using said phase mask to direct a second order beam of said phase mask at a recording material;
• and
• producing an interference pattern between said first beam and said second beam wherein said phase mask optically induces a perturbation on the index of refraction in a recording material to form said gratings.