An Optical Device and Associated Systems

A radiation source system comprising:

• an alignment system including a diffractive optical system and configured to:
• determine a position of a beam of electromagnetic radiation relative to a reference position in a reference plane and for determining a direction of the beam relative to a reference direction in the reference plane;
• and
• project onto a detection plane an image representative of the beam intersecting the reference plane;
• and
• wherein the diffractive optical system comprises a first lens and second lens and is operative to diffract the electromagnetic radiation into different diffraction orders, such that the first lens is operative to create a first projection of a first specific one of the different diffraction orders onto a first location in the detection plane and the second lens is operative to create a second projection of a second specific one of the different diffraction orders onto a second location in the detection plane different from the first location.

An alignment system, comprising:

• a diffractive optical system comprising first and second lenses;
• wherein,
• the alignment system configured to:
• determine a position of a beam of electromagnetic radiation relative to a reference position in a reference plane and for determining a direction of the beam relative to a reference direction in the reference plane;
• and
• project onto a detection plane an image representative of the beam intersecting the reference plane;
• and
• the diffractive optical system is operative to diffract the electromagnetic radiation into different diffraction orders, such that the first lens is operative to create a first projection of a first specific one of the different diffraction orders onto a first location in the detection plane and the second lens is operative to create a second projection of a second specific one of the different diffraction orders onto a second location in the detection plane different from the first location

A lithographic apparatus comprising,

• a radiation source system comprising:
• an alignment system including a diffractive optical system and configured to:
• determine a position of a beam of electromagnetic radiation relative to a reference position in a reference plane and for determining a direction of the beam relative to a reference direction in the reference plane;
• and
• project onto a detection plane an image representative of the beam intersecting the reference plane;
• and
• wherein the diffractive optical system comprises a first lens and second lens and is operative to diffract the electromagnetic radiation into different diffraction orders, such that the first lens is operative to create a first projection of a first specific one of the different diffraction orders onto a first location in the detection plane and the second lens is operative to create a second projection of a second specific one of the different diffraction orders onto a second location in the detection plane different from the first location.