A new technique is introduced to replace DOEs that are used for illumination in lithographic
projectors with polarization computer generated holograms (PCGHs) that produce both arbitrary
intensity and arbitrary polarization state in the illumination pupil. The additional capability of
arbitrary polarization state adds an additional degree of freedom for source-mask optimization.
The PCGHs are similar in design and construction to DOEs, but they incorporate polarizationsensitive
elements. Three experiments are described that demonstrate different configurations of
PCGHs deigned to produce a tangentially polarized ring. Measurements of ratio of polarization
and polarization orientation indicate that all three configurations performed well. Experimetns
are performed with visible (λ = 632.8nm) light.
It is shown that once the diffusely scattered polarization properties are calibrated, the texture orientation can
be calculated directly from diattenuation and retardance. Polarization scattering properties are studied for a
rough aluminum surface with one-dimensional rough texture and well-defined orientation. Functions of Mueller
matrix elements related to sample orientation about the normal via the arctangent function are investigated.
The Mueller matrix bidirectional reflectance distribution function is measured for a linearly sanded aluminum
sample. Sinusoidal fits to the Mueller matrix show that the angular orientation of the data can be recovered
explicitly from its properties.
Understanding the interaction of polarized light with materials is critical to applications such as remote
sensing, laser radar, and quality control. The availability of angular and spatial information add additional dimensions
to this understanding.
A facility is constructed for Mueller Matrix Bidirectional Reflectance Distribution (MMBRDF) imaging.
Polarized light at near infrared and visible wavelengths is scattered from samples ranging from bare metals to complex
organic structures with various textures and orientations. The resulting scattered polarized light is measured with a
Mueller matrix active imaging polarimeter.
The in-plane MMBRDF is measured for a sanded aluminum sample as a demonstration of the facility. The
aluminum is found to be a weak depolarizer, with a somewhat higher depolarization index at specular angles.
Retardance is dominated by its linear component and is close to 180° for the majority of angles. Diattenuation is weak,
especially in the specular region, and increases in the region further away from specular angles.
The in-plane Mueller matrix bidirectional reflectance distribution function (MMBRDF) is measured for a Spectralon
calibration target with a reflectance of 99%. Measurements are acquired using a Mueller matrix active imaging,
goniometric polarimeter operated in the near infrared at 1550nm. The Spectralon is measured for both incident and
scattering angles from -80 degrees to 80 degrees to within 20 degrees of retro-reflection. A range of polarization states
is generated and scattered polarization states are analyzed by means of a dual rotating retarder Mueller matrix
polarimeter. Complete Mueller matrix data is measured with a high-resolution camera in image form.
Polarization scatter data is presented in Mueller matrix angular arrays. As expected the Spectralon is a strong
depolarizer and weak s-plane oriented diattenuator. It was also a weak retarder. Diattenuation and retardance are
strongest at horizontal and vertical polarizations, and weakest for circular polarization states.