Design and fabrication of diffractive optical elements by use of gray-scale photolithography

Sohn, Jin Seung; Lee, Myung Bok; Kim, Wan Chin; Cho, Eun Hyung; Kim, Tae Wan; Yoon, Chan Young; Park, No Cheol; Park, Young Pil

doi:10.1364/ao.44.000506

Cited by 25 publications

(20 citation statements)

References 3 publications

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“…Because of this, patterns can be introduced into the material with a prescribed optical density distribution. These patterns are useful for producing three-dimensional profiles through UV photolithography, with diverse applications in micro-optics [12][13][14][15][16].…”

Section: Hebs Glass Grayscale Mask Writingmentioning

confidence: 99%

Efficient fiber to waveguide coupling structure for optical systems integration using grayscale lithography

Dillon¹,

Chen²,

Murakowski³

et al. 2007

SPIE Proceedings

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Silicon photonics is an area of active research and commercial interest due in part to its leveraging of the existing mature fabrication processes and infrastructure of the CMOS integrated circuit industry. Its suitability for use at the telecom wavelengths, low cost, and compact devices enhance the value of silicon for photonics applications. One critical issue that continues to be investigated is the efficient coupling of optical signals between the outside world and the photonic chip, which is hampered by the large optical mode mismatch between the glass fiber and high index contrast silicon waveguide. We introduce a new device that enables efficient coupling from the fiber to single mode silicon waveguide called the vertical J-coupler, so named in reference to its parabolic shape. Grayscale lithography is used to fabricate the three-dimensional topology of the coupler, enabled by the high energy beam sensitive (HEBS) glass grayscale photomask. The principle of operation is total internal reflection, which is inherently polarization insensitive and broadband. Electro-magnetic simulations validate the efficient operation of the device while experimental results demonstrate its successful operation in coupling light into the silicon waveguide.

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Section: Hebs Glass Grayscale Mask Writingmentioning

confidence: 99%

Efficient fiber to waveguide coupling structure for optical systems integration using grayscale lithography

Dillon¹,

Chen²,

Murakowski³

et al. 2007

SPIE Proceedings

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“…15 A method that uses gray-scale images has been introduced to compensate the intensity difference in photolithography. 16,17 However, it is difficult to apply gray-scale images in projection microstereolithography because the intensity distribution for each micro-lens should be considered. In this research, micro-lens arrays are fabricated with segmented cross-sectional images and without a stacking process in order to improve the precision.…”

Section: Introductionmentioning

confidence: 99%

Fabrication of a micro-lens array with a nonlayered method in projection microstereolithography

Park

Kim

et al. 2010

Int. J. Precis. Eng. Manuf.

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A fabrication method which is to make micro-lens arrays (MLAs) without a stacking process in projection microstereolithography is described. This method has two merits. First, the fabrication time can be reduced due to the use of one cross-sectional image. Second, the surface quality can be improved due to non-layer fabrication. A photocurable resin, which has low yellowing for adaption to a micro-lens, is synthesized. For precise fabrication of micro-lens arrays, the fabrication condition is estimated through curing experiments. Each micro-lens of the array is individually fabricated with a specific exposure time because the light intensity is not uniformly distributed. To verify this method, micro-lens arrays are fabricated in various dimensions. The limitations of such fabrication are also investigated.

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“…Those are slow temperature change in LD and very fast mode hop of LD. Even though slow variation of chromatic aberration can be corresponded with an actuator, fast variation of chromatic aberration by LD mode hop has to be resolved by optics (Sohn et al 2005). Following the study of Milster (1999), chromatic aberration can be reduced by use of a small SIL and a DOE.…”

Section: Introductionmentioning

confidence: 99%

“…Therefore, to minimize the harmful effect of a chromatic aberration, it is prefered to use a small SIL and a special optical element which has inverse dispersion to the dispersion of SIL. As a DOE has an inverse optical power to the refractive optical elements, it is often used to reduce an unwanted chromatic aberration whose amount is changed very fast by mode hop of LD (Sohn et al 2005). Therefore, to reduce chromatic aberration in the dual layer NFR optics, a DOE is used.…”

Section: Introductionmentioning

confidence: 99%

Design of near-field recording optics using truncated hemispherical SIL with cover-layer incident dual recording layers

et al. 2006

Self Cite

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In this paper, we propose a novel optics design for media inside near-field recording (NFR) using a truncated hemispherical solid immersion lens (HMS). To obtain strong advantage of data protection and high data capacity simultaneously, a truncated HMS based near field optics with cover-layer incident dual recording layers is designed. In this design, to improve the small optical tolerance of the truncated HMS unit and to adjust dual focusing positions, an additional aspheric lens surface is added on top of the truncated HMS and it is combined with zoom optics composed of two single lenses having a low numerical aperture (NA). Also, to compensate for chromatic aberration, which is a serious problem for optics using a blue laser diode, a diffractive optical element is also designed. Using zoom optics, an additional aspheric lens surface, and a diffractive optical element together, the wavefront aberration and chromatic aberration are effectively reduced in a broad range of cover-layer thicknesses and wavelength variations. In addition, in this paper, the effect of a gap induced aberration is investigated by analyzing the different behavior of each TM and TE wave for the cover-layer incident NFR optics.

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Design and fabrication of diffractive optical elements by use of gray-scale photolithography

Cited by 25 publications

References 3 publications

Efficient fiber to waveguide coupling structure for optical systems integration using grayscale lithography

Efficient fiber to waveguide coupling structure for optical systems integration using grayscale lithography

Fabrication of a micro-lens array with a nonlayered method in projection microstereolithography

Design of near-field recording optics using truncated hemispherical SIL with cover-layer incident dual recording layers

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