Refractive index distribution measuring method and refractive index distribution measuring apparatus
A method includes measuring a transmitted wavefront of a test object by introducing reference light into the test object arranged in a medium having a refractive index different from a refractive index of the test object, and calculating a refractive index distribution of the test object by using a measurement result of the transmitted wavefront. The measuring step measures a first transmitted wavefront for a first wavelength and a second transmitted wavefront for a second wavelength different from the first wavelength. The calculating step calculates the refractive index distribution of the test object by removing a shape component of the test object utilizing measurement results of the first and the second transmitted wavefront, and a transmitted wavefront of a reference object arranged in the medium for each of the first and second wavelengths. The reference object has the same shape as the test object and a specific refractive index distribution.
1. A refractive index distribution measuring method comprising the steps of:
measuring a transmitted wavefront of a test object by introducing reference light into the test object that is arranged in a medium having a refractive index different from a refractive index of the test object; and
calculating a refractive index distribution of the test object by using a measurement result of the transmitted wavefront,
wherein the measuring step measures a first transmitted wavefront for a first wavelength and a second transmitted wavefront for a second wavelength different from the first wavelength, and
wherein the calculating step calculates the refractive index distribution of the test object by removing a shape component of the test object utilizing measurement results of the first and the second transmitted wavefront, and a transmitted wavefront of a reference object arranged in the medium for each of the first and second wavelengths, the reference object having the same shape as the test object and a specific refractive index distribution.
2. The refractive index distribution measuring method according to claim 1 , wherein the measuring step uses a shearing interferometer to measure the transmitted wavefront of the object.
3. The refractive index distribution measuring method according to claim 1 , wherein the measuring step uses a Hartmann sensor to measure the transmitted wavefront of the object.
4. A production method for an optical element comprising the steps of:
molding the optical element; and
evaluating a molded optical element by measuring refractive index distribution of the optical element with a refractive index distribution measuring method, wherein the refractive index distribution measuring method includes the steps of:
measuring a transmitted wavefront of a test object by introducing reference light into the test object that is arranged in a medium having a refractive index different from a refractive index of the test object; and
calculating a refractive index distribution of the test object by using a measurement result of the transmitted wavefront,
wherein the measuring step measures a first transmitted wavefront for a first wavelength and a second transmitted wavefront for a second wavelength different from the first wavelength, and
wherein the calculating step calculates the refractive index distribution of the test object by removing a shape component of the test object utilizing measurement results of the first and the second transmitted wavefront, and a transmitted wavefront of a reference object arranged in the medium for each of the first and second wavelengths, the reference object having the same shape as the test object and a specific refractive index distribution.
5. A refractive index distribution measuring apparatus comprising:
a light source configured to emit light having a first wavelength and light having a second wavelength;
a measuring unit configured to measure a transmitted wavefront of a test object arranged in a medium having refractive index different from that of the test object by using the light from the light source; and
an operation unit configured to calculate a refractive index distribution of the test object based on a first transmitted wavefront measured for the first wavelength and a second transmitted wavefront measured for the second wavelength,
wherein the operation unit calculates the refractive index distribution of the test object by removing a shape component of the test object utilizing measurement results of the first and second transmitted wavefronts, and a transmitted wavefront of a reference object arranged in the medium for each of the first and second wavelengths, the reference object having the same shape as that of the test object and a specific refractive index.
6. The refractive index distribution measuring apparatus according to claim 5 , wherein the measuring unit includes a shearing interferometer.
7. The refractive index distribution measuring apparatus according to claim 5 , wherein the measuring unit includes a Hartmann sensor.