Tunable spectral slicer and methods of use

A method for filtering an input optical beam, comprising:

• splitting the input optical beam into a first optical beam and a second optical beam using a first beamsplitter, wherein the first beamsplitter is a dichroic beamsplitter that substantially transmits the first optical beam and substantially reflects the second optical beam:
• filtering the first optical beam by transmitting the first optical beam through a first spectral slicing module having a first passband, wherein the first spectral slicing module comprises a first longpass filter and a first shortpass filter aligned along a first optical axis, wherein at least one of the first longpass filter or the first shortpass filter is rotatable relative to the first optical axis;
• filtering the second optical beam by transmitting the second optical beam through a second spectral slicing module having a second passband, wherein the second spectral slicing module comprises a second longpass filter and a second shortpass filter aligned along a second optical axis, wherein at least one of the second longpass filter or the second shortpass filter is rotatable relative to the second optical axis, wherein the first and second passbands both include a first range of wavelengths, wherein the first beamsplitter has a transition region that spans a second range of wavelengths, and wherein the second range of wavelengths is narrower than the first range of wavelengths;
• and
• combining the first and second optical beams into an output optical beam using a second beamsplitter.

A method for configuring an imaging system, comprising:

• splitting an input optical beam into a first optical beam and a second optical beam using a first beamsplitter, wherein the first beamsplitter is a dichroic beamsplitter that substantially transmits the first optical beam and substantially reflects the second optical beam:
• filtering the first optical beam by transmitting the first optical beam through a first spectral slicing module having a first passband, wherein the first spectral slicing module comprises a first longpass filter and a first shortpass filter aligned along a first optical axis, wherein at least one of the first longpass filter or the first shortpass filter is rotatable relative to the first optical axis;
• filtering the second optical beam by transmitting the second optical beam through a second spectral slicing module having a second passband, wherein the second spectral slicing module comprises a second longpass filter and a second shortpass filter aligned along a second optical axis, wherein at least one of the second longpass filter or the second shortpass filter is rotatable relative to the second optical axis, wherein the first and second passbands both include a first range of wavelengths, wherein the first beamsplitter has a transition region that spans a second range of wavelengths, and wherein the second range of wavelengths is narrower than the first range of wavelengths:
• and
• combining the first and second optical beams into an output optical beam using a second beamsplitter.