Interferometric systems and methods

An interferometric system comprising:

• at least one light source including a deep ultraviolet light source configured to generate first light having a wavelength within a window in the deep ultraviolet region of the electromagnetic spectrum within which a local minimum in the absorption coefficient of oxygen occurs, wherein the wavelength is approximately 121.6 nm, and wherein the at least one light source is further configured to generate additional light that includes visible light or near-ultraviolet light and that is directed toward a target location;
• a lens device that receives a first portion of the generated first light and directs the first portion of the generated first light toward the target location, wherein at least a part of a first light path between the deep ultraviolet light source and the target location is other than at a high vacuum;
• and
• a beam splitting device that is positioned between the deep ultraviolet light source and the lens device,
• wherein interference occurs between a second portion of the generated first light and either the first portion of the generated first light or reflected light received by lens device from the target location after the first portion of the generated first light is directed toward the target location.

A method of performing interferometry, the method comprising:

• providing visible light to a target location;
• generating additional light at a light source, wherein a wavelength of the generated additional light is within a window in the deep ultraviolet region of the electromagnetic spectrum within which a local minimum in the absorption coefficient of Oxygen occurs, the window being at least one of about 1.0 nm and about 2.0 nm in width, wherein the wavelength is approximately 121.6 nm;
• transmitting a first portion of the generated additional light to the target location by way a beam splitter and at least one lens device, wherein at least a part of a light path between the light source and the target location is other than at a high vacuum;
• communicating reflected light received from the target location, by way of the at least one lens device and the beam splitter, to a further location at which is positioned a camera system, wherein the reflected light includes at least some of the first portion of the generated additional light;
• further transmitting a second portion of the generated additional light to the camera system, wherein the second portion of the generated additional light reaches the camera system after experiencing reflection at each of the beam splitter and a mirror;
• and
• producing, at the camera system, an image indicative of interference between the reflected light and the second portion of the generated additional light.