The present disclosure describes optical radiation sensors and detection techniques that facilitate assigning a specific wavelength to a measured photocurrent. The techniques can be used to determine the spectral emission characteristics of a radiation source. In one aspect, a method of determining spectral emission characteristics of incident radiation includes sensing at least some of the incident radiation using a light detector having first and second photosensitive regions whose optical responsivity characteristics differ from one another. The method further includes identifying a wavelength of the incident radiation based on a ratio of a photocurrent from the first region and a photocurrent from the second region.

The present disclosure describes optical radiation sensors and detection techniques that facilitate assigning a specific wavelength to a measured photocurrent. The techniques can be used to determine the spectral emission characteristics of a radiation source. In one aspect, a method of determining spectral emission characteristics of incident radiation includes sensing at least some of the incident radiation using a light detector having first and second photosensitive regions whose optical responsivity characteristics differ from one another. The method further includes identifying a wavelength of the incident radiation based on a ratio of a photocurrent from the first region and a photocurrent from the second region.

A method of determining a reference calibration setting for an adaptive optics system (1) comprising a detecting device (8) for detecting light from an object (5); and at least one controllable wavefront modifying device (9) arranged such that light from the object (5) passes via the wavefront modifying device (9) to the detecting device (8). The method comprises the steps of: arranging (100) a light-source between the object (5) and the wavefront modifying device (9) to provide a reference light beam to the detecting device (8) via the wavefront modifying device; for each of a plurality of orthogonal wavefront modes of the wavefront modifying device: controlling (101) the wavefront modifying device to vary a magnitude of the orthogonal wavefront mode over a predetermined number of magnitude settings; acquiring (102) a series of readings of the detecting device, each reading corresponding to one of the magnitude settings; determining (103) a quality metric value indicative of an information content of the reading for each reading in the series of readings, resulting in a series of quality metric values; and determining (106) a reference parameter set for the wavefront modifying device corresponding to an optimum quality metric value based on the series of quality metric values.

A method of determining a reference calibration setting for an adaptive optics system (1) comprising a detecting device (8) for detecting light from an object (5); and at least one controllable wavefront modifying device (9) arranged such that light from the object (5) passes via the wavefront modifying device (9) to the detecting device (8). The method comprises the steps of: arranging (100) a light-source between the object (5) and the wavefront modifying device (9) to provide a reference light beam to the detecting device (8) via the wavefront modifying device; for each of a plurality of orthogonal wavefront modes of the wavefront modifying device: controlling (101) the wavefront modifying device to vary a magnitude of the orthogonal wavefront mode over a predetermined number of magnitude settings; acquiring (102) a series of readings of the detecting device, each reading corresponding to one of the magnitude settings; determining (103) a quality metric value indicative of an information content of the reading for each reading in the series of readings, resulting in a series of quality metric values; and determining (106) a reference parameter set for the wavefront modifying device corresponding to an optimum quality metric value based on the series of quality metric values.

A method of designing a multifocal ophthalmic lens with one base focus and at least one additional focus, capable of reducing aberrations of the eye for at least one of the foci after its implantation, comprising the steps of: (i) characterizing at least one corneal surface as a mathematical model; (ii) calculating the resulting aberrations of said corneal surface(s) by employing said mathematical model; (iii) modelling the multifocal ophthalmic lens such that a wavefront arriving from an optical system comprising said lens and said at least one corneal surface obtains reduced aberrations for at least one of the foci. There is also disclosed a method of selecting a multifocal intraocular lens, a method of designing a multifocal ophthalmic lens based on corneal data from a group of patients, and a multifocal ophthalmic lens.

Disclosed are a decoherence processing method and system, and a coherent light receiving apparatus. The coherent light receiving apparatus comprises a plurality of photoelectric conversion units. The method comprises: performing phase comparison between electric signals, obtained by means of conversion performed by at least two of a plurality of photoelectric conversion units, and a reference signal to obtain a corresponding phase difference; according to the obtained phase difference, respectively performing phase compensation on the electric signals obtained by means of conversion performed by the at least two photoelectric conversion units, so as to obtain at least two compensated electric signals of the photoelectric conversion units; and using the at least two compensated electric signals of the photoelectric conversion units to superpose and output electric signals.

Disclosed are a decoherence processing method and system, and a coherent light receiving apparatus. The coherent light receiving apparatus comprises a plurality of photoelectric conversion units. The method comprises: performing phase comparison between electric signals, obtained by means of conversion performed by at least two of a plurality of photoelectric conversion units, and a reference signal to obtain a corresponding phase difference; according to the obtained phase difference, respectively performing phase compensation on the electric signals obtained by means of conversion performed by the at least two photoelectric conversion units, so as to obtain at least two compensated electric signals of the photoelectric conversion units; and using the at least two compensated electric signals of the photoelectric conversion units to superpose and output electric signals.

The invention relates to an optoelectronic chip comprising the following elements: a light inlet; a wavelength-sensitive optical filter; a first photoelectric element for measuring a first light intensity, particularly a first photodiode, the first photoelectric element being arranged such that light penetrating the optoelectronic chip via the light inlet, transmitted by the filter, hits the first photoelectric element; and a second photoelectric element for measuring a second light intensity, particularly a second photodiode, the second photoelectric element being arranged such that the light penetrating the optoelectronic chip via the light inlet, which is reflected by the filter, hits the second photoelectric element.

A filter for removing coherent radiation from a source in a field of view, substantially independent of the size of the source, comprises a first reticle 22 located in the path of received light 21, a first lens 23 producing an optical transform of the first reticle 22 at a second reticle 24 located in the image plane of the first lens 23, a second lens 25 producing an optical transform of the second reticle 24 and a third reticle 26 located in the image plane of the second lens 25. The arrangement is such that the spatial transmittance of the third reticle 26 is selected to block at least part of the diffracted image of the first reticle 22 produced in the image plane of the second lens 25 and characteristic of the coherent radiation. Preferably the optical transforms are Fourier Transforms. A monochromatic coherent source in the field of view produces a pattern of diffracted energy in the image plane of the second lens which is independent of the size of the source. Thus, by providing a suitable reticle 26 in the image plane of the second lens light from a coherent source in the field of view can be blocked while polychromatic light is transmitted. The first and second reticles may be periodic picket-fence reticles or different spatial frequencies may be used for the first and third reticles so as to vary the stop-band characteristics of the filter.

Method, product and blocking element of short wavelengths in LED-type light sources consisting of a substrate with a pigment distributed on its surface and, in that said pigment has an optical density such that it allows the selective absorption of short wavelengths between 380 nm and 500 nm in a range between 1 and 99%.