A toroidal optical device can include a ring mirror defining a toroidal optical cavity symmetric about an axis and an optical coupler situated inside the toroidal optical cavity. The optical coupler can be situated to direct an input light first received from outside the toroidal optical cavity propagating inside the toroidal optical cavity, to multiply reflect from the ring mirror inside the toroidal optical cavity. A method includes producing one or more additional ring mirrors defining a toroidal optical cavity symmetric about a sagittal axis using a first ring mirror as a master form, and affixing an optical coupler inside the optical cavity to at least one of the one or more additional ring mirrors.

An optical device disperses a wavelength of light and includes: a dispersion element configured to transmit incident light and disperse the incident light so that an optical path is different for each wavelength and to generate first dispersed light; and a reflection unit including four reflection surfaces sequentially reflecting the first dispersed light. The first dispersed light sequentially reflected from the four reflection surfaces is incident on the dispersion element and is transmitted through the dispersion element.

A headset includes a compact wide field of view optics block. The headset includes a display element and an optics block. The display element is configured to generate image light. The optics block is configured to direct the image light to an eyebox. The optics block includes a projection lens and a panoramic lens. The projection lens has a first diameter and is adjacent to the display element and is configured to receive the image light from the display element. The panoramic lens is positioned between the projection lens and the eyebox. The panoramic lens has a second diameter that is larger than the first diameter and is configured to provide the image light that has been transmitted by the projection lens to the eyebox.

A demodulator can include an optical resonator. The optical resonator can include a resonant cavity that extends between a first surface that is partially reflective and a second surface that is at least partially reflective. The first surface can receive a phase-modulated optical signal that has a time-varying phase. The resonant cavity can accumulate resonant optical signal energy based at least in part on the phase-modulated optical signal. The first surface can direct a fraction of the resonant optical signal energy out of the optical resonator to form an intensity-modulated optical signal that has a time-varying intensity. A data detector can receive at least a portion of the intensity-modulated optical signal and, in response, generate an intensity-modulated electrical signal that has a time-varying intensity that corresponds to the time-varying phase of the phase-modulated optical signal.

Disclosed are optical communications systems and optical receivers including one or more optical cavity resonators. In particular, disclosed are methods and apparatus that allow for beam pointing to be maintained while permitting the receiver to tune the optical resonator to suit the wavelength, data rate and modulation format of the incoming optical signal, without requiring a coherent receiver or adaptive optics in addition to optical resonators.

An optical cavity includes: a first elliptical mirror, having a first focal axis A.sub.1, and designed to reflect a light beam emitted by a light source; a second elliptical mirror, having a second focal axis A.sub.2; a third elliptical mirror, having a third focal axis A.sub.3, the light beam exiting from the third elliptical mirror being designed to be received by a detector; a first reflector, arranged to reflect the light beam exiting from first elliptical mirror in the direction of the second elliptical mirror, and arranged to reflect the light beam exiting from second elliptical mirror in the direction of the third elliptical mirror; the first, second and third elliptical mirrors being arranged so that A.sub.1, A.sub.2 and A.sub.3 have a point of intersection F, corresponding to a focus common to the first, second and third elliptical mirrors.

A method for designing a device for multi-plane conversion of light radiation, the device implementing a plurality M of phase masks intercepting the light radiation in order to phase-shift the radiation for applying a predetermined transformation to the light radiation. First and second mode families (u,v) with separable variables (x,y) are defined. A number N of pairs of indices {i,j}.sub.k is chosen to form first and second used mode families, respectively, by selecting the modes of index pairs {i,j}.sub.k from the first mode family and from the second mode family, respectively. Next, the phase-shift quantities (x,y) are established, the M phase masks making it possible to transform each mode of index pairs {i,j).sub.k of the first used mode family into the mode of the same index pair {i,j}.sub.k of the second used mode family. A phase plate may be obtained by means of the design method and used in a multi-plane conversion device.

A toroidal optical device can include a ring mirror defining a toroidal optical cavity symmetric about an axis and an optical coupler situated inside the toroidal optical cavity. The optical coupler can be situated to direct an input light first received from outside the toroidal optical cavity propagating inside the toroidal optical cavity, to multiply reflect from the ring mirror inside the toroidal optical cavity. A method includes producing one or more additional ring mirrors defining a toroidal optical cavity symmetric about a sagittal axis using a first ring mirror as a master form, and affixing an optical coupler inside the optical cavity to at least one of the one or more additional ring mirrors.

An optical configuration including axiconical elements that serve as parts of a resonator or an optical chain of an amplifier for an active laser volume with a large transverse dimension. The system may include a single-fold or multiple-folds axiconical elements. One of the system's advantages is providing the means to produce, even with a stable resonator, a high-quality and well-controlled beam, utilizing efficiently a wide active laser medium.

A device includes a light splitter configured to receive a source light beam from a light source and split the source light beam into separate light beams, each emitted through an outlet. The device also includes resonators, each of which is optically coupled to at least one of the outlets and is configured to steer at least one of the light beams.