Obviousness

The obviousness of US patent 12240054 under 35 U.S.C. § 103 can be argued by combining the teachings of prior art references. The core innovation of US12240054 lies in using a multi-clad fiber with an inner fiber core and at least one outer ring core, and selectively coupling a laser beam (or different laser beams) into these distinct regions to generate different output beam profile characteristics for various applications.

Independent Claims of US12240054:

Claim 1 (System): A system comprising a multi-clad fiber (with an inner fiber core and at least one outer ring core), a first optical fiber guiding a first input laser beam, and a second optical fiber guiding a second input laser beam to the multi-clad fiber. The system is configured to couple at least one of: the first input laser beam at least into the inner fiber core, or the second input laser beam at least into the at least one outer ring core of the multi-clad fiber.

Claim 11 (Method): A method comprising guiding a first input laser beam by a first optical fiber and a second input laser beam by a second optical fiber to a fiber end of a multi-clad fiber (with an inner fiber core and at least one outer ring core). The method includes coupling these laser beams into the fiber end, where at least one of the following occurs: the first input laser beam is coupled at least into the inner fiber core, or the second input laser beam is coupled at least into the at least one outer ring core. An output laser beam is generated, whose beam profile characteristic differs depending upon the coupling.

Prior Art Combination for Obviousness:

A strong argument for obviousness can be made by combining US20020071647A1 (Manzur) with DE 38 33 992 A1 (Messerschmitt-Boelkow-Blohm).

1. US20020071647A1 (Manzur) - Multi-clad Fiber Structure:
   The title of US20020071647A1, "Multi-clad optical fiber and amplifier," strongly suggests the disclosure of a multi-clad optical fiber. In the field of laser technology and fiber optics, a "multi-clad fiber," especially a "double-clad fiber" as frequently referenced in US12240054, commonly refers to a fiber structure comprising an inner fiber core and at least one outer ring core, surrounded by different cladding layers. This reference would thus teach the fundamental multi-clad fiber structure required by claims 1 and 11. The "amplifier" aspect further indicates its relevance to laser applications, often involving high power.

2. DE 38 33 992 A1 (Messerschmitt-Boelkow-Blohm) - Varying Coupling for Different Beam Properties:
   As described in the background of US12240054, DE 38 33 992 A1 "describes a method for achieving specific laser beam properties in which the laser beams of two laser beam sources are coupled into a conventional optical fiber at different coupling angles." This prior art teaches the general concept of varying coupling conditions into an optical fiber to modify the output laser beam's characteristics. While DE 38 33 992 A1 uses a "conventional optical fiber" and its beam formation is "dependent on the wavelength," it clearly establishes the principle of manipulating input coupling to alter output beam properties.

Motivation to Combine:

A person having ordinary skill in the art (PHOSITA) in 2010 (the priority date of US12240054) would have been motivated to combine the teachings of Manzur and DE 38 33 992 A1 for the following reasons:

• Addressing Known Limitations: US12240054 explicitly states that the method of DE 38 33 992 A1 "proves not to be optimum on account of its disproportionate complexity for such cases and its limiting specialization in applications of a different type" and is "limited to the beam formation dependent on the wavelength." A PHOSITA, seeking to overcome these limitations and achieve more versatile, application-specific beam profile changes, would naturally look to more advanced fiber structures beyond the "conventional optical fiber" of DE 38 33 992 A1.
• Leveraging Inherent Fiber Properties: Manzur's disclosure of a multi-clad optical fiber would immediately suggest to a PHOSITA that such a fiber inherently provides multiple distinct light-guiding paths (e.g., the inner core and the outer ring core). Knowing from DE 38 33 992 A1 that modifying coupling conditions into any fiber can alter output beam properties, it would be an obvious design choice to extend this principle to a multi-clad fiber by selectively coupling laser beams into its distinct inner core or outer ring core. This directly exploits the structural advantage of a multi-clad fiber.
• Achieving Desired Beam Profiles for Material Processing: The patent itself highlights the desire for different beam qualities in material processing, such as a "comparatively good beam quality with a sharp focus... for a laser cutting process, and, in contrast, a ‘reduced’ beam quality with a ‘blurred’ focus... particularly suitable for welding processes." A PHOSITA would recognize that coupling into a smaller inner core typically yields a higher beam quality and sharper focus, while coupling into a larger outer ring core (or both regions) can produce a wider, potentially more uniform beam profile. The motivation to achieve these well-known different beam characteristics for different laser processing tasks would drive the selective coupling into the different cores of a multi-clad fiber.
• Routine Design Choice for Multiple Sources: DE 38 33 992 A1 already describes coupling "laser beams of two laser beam sources" into a fiber. If a multi-clad fiber (Manzur) is known to have distinct guiding regions, it would be a routine design choice to guide these multiple laser beams (or sub-beams) via separate input optical fibers and selectively couple them into the corresponding core regions of the multi-clad fiber. This provides precise control over the power distribution and resulting beam profile, addressing the explicit objective of US12240054 to allow "an application-specific change to the laser beam characteristics with relatively little effort."

Therefore, a PHOSITA, motivated to overcome the limitations of prior art like DE 38 33 992 A1 and leverage the known structural advantages of multi-clad fibers (Manzur) to achieve versatile laser beam profiles for various applications, would have found it obvious to combine these references to arrive at the systems and methods claimed in US12240054. The selective coupling into different core regions of a multi-clad fiber to produce varying beam profiles is a logical and predictable outcome of such a combination, meeting the functional requirements articulated in the patent.