Title:
ウエッジを用いた回折型ビームホモジナイザ光学系
Document Type and Number:
Japanese Patent JP4332855
Kind Code:
B2
Abstract:
In a diffractive optical element (DOE) for diffracting a Gaussian distribution beam into a uniform or quasi-uniform power distribution beam on an image plane, step height errors or other manufacturing errors yield a zero-th order beam, cause interference between the diffracted beam and the zero-th order beam and invite power fluctuation. Instead of a parallel planar shape, a wedge-shaped DOE (3) having surfaces inclining at an angle in average separates the zero-th order beam from the diffraction beam (2), prevents the zero-th order beam from interfering with the diffraction beam (2) and suppress power fluctuation of the diffraction beam. The wedge angle satisfies an inequality § {³+(D/L)}/(n-1), where D is a diameter of the incident beam (3), n is a refractive index of the DOE (3), L is a distance between the DOE (3) and the image plane (5), and ³ is an angle viewing the uniform power pattern on the image plane from the center of the DOE (3).
Inventors:
Takayuki Hirai
Application Number:
JP2005166337A
Publication Date:
September 16, 2009
Filing Date:
June 07, 2005
Export Citation:
Assignee:
Sumitomo Electric Industries, Ltd.
International Classes:
G02B5/18; G02B27/09
Domestic Patent References:
| JP9061610A | ||||
| JP2002048908A | ||||
| JP3503578A | ||||
| JP2004230432A | ||||
| JP2002202414A |
Attorney, Agent or Firm:
Shigeki Kawase