A focal-length measuring apparatus for a sub-wavelength optical imaging device includes a laser, a beam-expanding and collimating system, a sub-wavelength optical imaging device, and a nanoscale stepped height standard sample block. The nanoscale stepped height standard sample block is connected to a power device, and the power device is connected to a computer control system. The nanoscale stepped height standard sample block is coated with a photoresist and includes a plurality of steps arranged at equal intervals Among all the steps, the heights of the steps gradually increase from a middle step to an upper side, and the values of the corresponding focal lengths decrease. While, the heights of the steps gradually decrease from the middle step to a lower side, and values of corresponding focal lengths increase. A wavelength of the laser is equal to a designed wavelength of an input light source of the sub-wavelength optical imaging device.

A lens refractive index detection device is disclosed which has a light source module, a lens center physical thickness detection module and a lens center optical thickness detection module. The light source module includes a first light source component and a second light source component for outputting a collimated light beam, a first light combining component, and a focusing component. The lens center physical thickness detection module includes a first imaging component and a second imaging component. The lens center optical thickness detection module includes a first photodetection component and a second photodetection component, a beam splitting component, a partial reflection mirror, and a movable reflection mirror. The lens refractive index detection device enables simple operation, fast and non-destructive on-line detection, and is also applicable to lenses with irregular surfaces, such as aspherical lenses, cylindrical lenses, and finished lenses. A lens refractive index detection method is also provided.

Some demonstrative embodiments include apparatuses, systems and/or methods of determining one or more parameters of a lens, For example, a computing device may be configured to process at least one depth map including depth information captured via a lens; and to determine one or more parameters of the lens based on the depth information.

A method implemented by computer means for determining at least one optical parameter of a lens of eyewear adapted for a person, the method comprising: an image reception step, during which at least a first image and a second image are received, the first image comprising a front view of the face of the person with at least one part of an eye of the person being directly visible, and the second image comprising a front view of the face of the person with said part of the eye of the person being visible through at least part of the lens, and an optical parameter determination step, during which at least one optical parameter of the lens is determined based on a comparison between said part on the first and the second image.

Some demonstrative embodiments include apparatuses, systems and/or methods of determining one or more optical parameters of a lens of eyeglasses. For example, a product may include one or more tangible computer-readable non-transitory storage media including computer-executable instructions operable to, when executed by at least one computer processor, enable the at least one computer processor to implement operations of determining one or more optical parameters of a lens of eyeglasses. The operations may include processing at least one image of an object captured via the lens; and determining the one or more optical parameters of the lens based on the at least one image.

Methods and systems for determining optical properties for light transmitted mediums are provided. One method includes acquiring one or more measured values indicative of a reflectance for a material, acquiring one or more measured values indicative of a transmittance for the material, and determining a set of calculated values for an index of refraction coefficient and an extinction coefficient from the one or more measured values indicative of reflectance and transmittance, respectively. The method includes identifying a calculated value from the set of calculated values for the index of refraction coefficient and a calculated value from the set of calculated values for the extinction coefficient that are within a threshold determined by the difference between the one or more measured values indicative of the reflectance or transmittance and a predicted reflectance or transmittance, respectively. The method includes determining a reflectance and transmittance for the material using the calculated values.

The invention is generally directed to an apparatus and a method for measuring a refractive index of a soft contact lens under a consistent pressure.

An ophthalmic measurement and laser surgery system includes: a laser source; a corneal topography subsystem; an axis determining subsystem; a ranging subsystem comprising an Optical Coherence Tomographer (OCT); and a refractive index determining subsystem. All of the subsystems are under the operative control of a controller. The controller is configure to: operate the corneal topography subsystem to obtain corneal surface information; operate the axis determining subsystem to identify one or more ophthalmic axes of the eye; operate the OCT to sequentially scan the eye in a plurality of OCT scan patterns, the plurality of scan patterns configured to determine an axial length of the eye; operate the refractive index determining subsystem so to determine an index of refraction of one or more ophthalmic tissues, wherein at least one of the corneal surface information, ophthalmic axis information, and axial length is modified based on the determined index of refraction.

A test fixture includes a base and an adjustable structure. The adjustable structure includes a limiting block, a locking block, and a fixing member. The limiting block is disposed on the base. The locking block is disposed on the base and abuts an edge of the limiting block to lock the limiting block in position. The fixing member is disposed on the limiting block to fix the limiting block on the base. When the locking block is moved from a first position to a second position, the locking block unlocks the limiting block, the fixing member is loosened, and the limiting block can rotate on the base. After the limiting block is rotated, the locking block is moved from the second position to the first position to lock the limiting block, and the fixing member is tightened to fix the limiting block on the base.

The present application relates to the measurement technology of the homogeneity in optical materials, and more particularly to a method for evaluating and controlling temperature influence on a homogeneity test for infrared optical materials. The precision of the test results is found to be affected by local small temperature changes of the sample during the homogeneity test for the refractive indexes of infrared optical materials, the invention establishes a two-dimensional numerical table in which the test precision requirements of a refractive index homogeneity test for infrared optical materials correspond to the ambient control temperatures in the test room corresponding to the influence of temperature changes on the refractive index of different infrared optical materials. In addition, related calculation formulas are established for theory analysis, numerical calculation and form-designing. The method of the present invention accurately guides the temperature control for the precision of the homogeneity test for infrared optical materials.