Optical coherence tomography systems for imaging a whole eye are provided including a sample arm including focal optics that are configured to rapidly switch between at least two scanning modes in less than about 1.0 second.

In some embodiments, systems, methods, and media for multiple reference arm spectral domain optical coherence tomography are provided which, in some embodiments, includes: a sample arm coupled to a light source; a first reference arm having a first path length; a second reference arm having a longer second path length; a first optical coupler that combines light from the sample arm and the first reference arm; a second coupler that combines light from the sample arm and the second reference arm; and an optical switch comprising: a first input port coupled to the first optical coupler; a second input coupled to the second coupler via an optical waveguide that induces a delay at least equal to an acquisition time of an image sensor; and an output coupled to the image sensor.

An optoelectronic device for a self-mixing interferometer includes a driver block, a semiconductor laser (SCL), a detector (DTC) and a switching network (SWN). The driver block is operable to provide a time modulated control signal, wherein the control signal has a periodic waveform. The semiconductor laser (SCL) is operable to emit a laser light with a time-dependent characteristics being a function of the control signal and a self-mixing interference optical feedback. The detector (DTC) is operable to generate a detection signal depending on the time-dependent characteristics. The switching network (SWN) is arranged to provide a time sequence of detection signals per period of the control signal.

A method to determine an absolute position of a first movable object using an interferometer system is described, said method comprising: providing first and second beams with a first light frequency from a first light source: providing further first and further second beams with a second (tunable) light frequency from a second light source: guiding the first and further first beams along a first axis to a reflective surface of the first object to obtain a first interferometer signal and guiding the second and further second beams along a second axis to a reflective surface of a second object to obtain a second interferometer signal, while changing the tunable frequency, detecting the first and further first interferometer signals detecting the second and further second interferometer signals, determining a first count offset and/or a further first count offset using a non-linear equation, and determining the absolute position of the first object.

A method for reconstructing a digital hologram of a surface having at least one three-dimensional feature thereon, including acquiring a digital hologram of the surface, reconstructing a wavefront based on the digital hologram, generating a phase map of at least a portion of the surface based on the wavefront, the phase map including phase ambiguities, obtaining at least one additional image of the surface, obtaining height data relating to the three-dimensional feature from the at least one additional image of the surface, the height data being obtained with a first precision, resolving the phase ambiguities based on the height data and deriving a height of the at least one three-dimensional feature based on the phase map following the resolving of the phase ambiguities therein, the height being derived with a second precision more precise than the first precision.

The invention provides a method to determine an absolute position of an object using an interferometer system, comprising the steps of: providing a light beam; splitting the light beam in a measurement beam and a reference beam; guiding the measurement beam along a measurement path towards a reflective measurement surface on the object; guiding the reference beam along a reference path towards a reflective reference surface on a reference object; receiving the measurement beam after reflection on the reflective measurement surface and the reference beam after reflection on the reflective reference surface at a detector; measuring a phase signal based on the measurement beam and the reference beam received by the detector, separating a cyclic error phase component from the phase signal, determining the absolute position of the object on the basis of the cyclic error phase component.