United States District Court, C.D. California
CIVIL MINUTES - GENERAL PROCEEDINGS (IN CHAMBERS): ORDER DENYING MOTIONS IN LIMINE  
DAVID O. CARTER, District Judge.
Before the Court are cross-motions in limine to preclude or limit the testimony of Plaintiff Newport Corporation's ("Newport's") expert, Dr. Philip Bucksbaum ("Dr. Bucksbaum"), and the testimony of Defendant Lighthouse Photonics Incorporated's ("Lighthouse's") expert, Dr. John Nightingale ("Dr. Nightingale"). See generally Pl.'s Mot. (Dkt. 372); Def.'s Mot. (Dkt. 374).
In this suit, Newport alleges that Lighthouse's "Sprout" family of solid state lasers infringe on three of its patents. See generally FAC (Dkt. 20).
In July 2013, Newport and Lighthouse filed a series of applications and motions related to a variety of discovery disputes that arose between them. Parties resolved the disputes by a stipulated order, in which Lighthouse agreed to provide a Sprout laser for any "tests as deemed necessary by Dr. Bucksbaum" for up to two and a half days. Stipulation and Order Resolving Discovery Disputes, November 13, 2013 (Dkt. 360). The inspections occurred on December 18 and 19, 2013. Watson Decl., Exh. B, ¶ 46.
The present motions arise out of the circumstances surrounding those inspections. They center on the fact that Newport's expert, Dr. Bucksbaum, relied on a design document produced by Lighthouse, which Lighthouse now explains is an inaccurate representation of the actual specifications of the Sprout lasers. Lighthouse argues that Dr. Bucksbaum's reliance on the design document renders his testimony irrelevant and unreliable. Newport argues that Lighthouse's expert, Dr. Nightingale, should be precluded from criticizing Dr. Bucksbaum's testing on this basis because such testimony contradicts previous representations made by Lighthouse.
II. LEGAL STANDARD
Under Federal Rule of Evidence 702, expert testimony is admissible only if it is both relevant and reliable. Daubert v. Merrell Dow Pharms., Inc. , 509 U.S. 579, 589 (1993). The district court acts as a gatekeeper, excluding expert testimony where it is either irrelevant or unreliable. Barabin v. AstenJohnson, Inc. , 700 F.3d 428, 431 (9th Cir. 2012). In making this gatekeeping determination in patent cases, a district court follows the law of its own regional circuit. Micro Chem., Inc. v. Lextron, Inc. , 317 F.3d 1387, 1390-91 (Fed. Cir. 2003).
District courts consider the following factors when assessing admissibility of expert testimony: "(1) a theory or technique can be (and has been) tested;' (2) whether the theory or technique has been subjected to peer review and publication;' (3) the known or potential rate of error;' and (4) whether it is generally accepted in the scientific community." Wagner v. Cnty. of Maricopa , 673 F.3d 977, 989 (9th Cir. 2012) (quoting Daubert , 509 U.S. at 593-94).
A. Lighthouse's Motion to Preclude the Testimony of Dr. Bucksbaum
Newport offers the expert testimony of Dr. Philip Bucksbaum, a physics professor at Stanford University, who opines that the "TEM00 mode size in the laser crystal is smaller than a pump beam diameter in the laser crystal." See Watson Decl., Exh. C. Lighthouse moves to preclude his testimony for two reasons: (1) his opinion is not based on relevant or reliable data because he did not measure the TEM00 mode size and (2) his methodologies for measuring the pump beam size are not generally accepted.
1. Reliance on Sprout Laser Design Document
Dr. Bucksbaum compares the widths of two laser beams: (1) the TEM00 (or cavity mode) beam and (2) the pump beam. Lighthouse argues that Dr. Bucksbaum's testimony is irrelevant and unreliable because, instead of measuring the TEM00 mode size himself, he relied on design documents produced by Lighthouse. The Court rejects ...