An apparatus includes an adaptive retro-reflector device. The adaptive retro-reflector device includes a standard retro-reflector. In operation, the retro-reflector receives an incident optical signal and outputs a returned optical signal. The returned optical signal exhibits a divergence. The adaptive retro-reflector device includes an elastomeric interface. The elastomeric interface is in optical communication with the retro-reflector such that the incident optical signal passes through the elastomeric interface to the retro-reflector and such that the returned optical signal from the retro-reflector passes through the elastomeric interface. The elastomeric interface includes an interface surface. The apparatus includes a standard actuator. The actuator in operation communicates with the elastomeric interface so as to deform the interface surface, thereby controlling the divergence. Optionally, the elastomeric interface includes a standard elastomeric membrane and a standard optically transparent optical fluid. The optically transparent optical fluid is at least partially encapsulated by the elastomeric membrane.

An apparatus includes an adaptive retro-reflector device. The adaptive retro-reflector device includes a standard retro-reflector. In operation, the retro-reflector receives an incident optical signal and outputs a returned optical signal. The returned optical signal exhibits a divergence. The adaptive retro-reflector device includes an elastomeric interface. The elastomeric interface is in optical communication with the retro-reflector such that the incident optical signal passes through the elastomeric interface to the retro-reflector and such that the returned optical signal from the retro-reflector passes through the elastomeric interface. The elastomeric interface includes an interface surface. The apparatus includes a standard actuator. The actuator in operation communicates with the elastomeric interface so as to deform the interface surface, thereby controlling the divergence. Optionally, the elastomeric interface includes a standard elastomeric membrane and a standard optically transparent optical fluid. The optically transparent optical fluid is at least partially encapsulated by the elastomeric membrane.

Optical detection system having: an emitter providing a collimated light beam; a receiver receiving the collimated light beam, the receiver having: a receiver lens converging the collimated light beam along an optical axis, and a corner reflector, the corner reflector having three planar surfaces perpendicular to each other and a symmetry axis coinciding with an intersection point of the three planar surfaces and forming an equal angle with each of the planar surfaces, the corner reflector reflecting the collimated light beam about the symmetry axis. The optical axis of the receiver lens is parallel to the symmetry axis of the corner reflector.

Techniques are disclosed to enable manufacture of open-air corner-cube retroreflectors having a corner-cube cavity. The techniques involve additively forming a substrate by way of additive manufacturing technologies such as three-dimensional printing technologies. The techniques further involve optionally machining the additively formed surface of the substrate and replicating a reflective surface in the corner-cube cavity using a master that is coated with a reflective material. An adhesive is applied to the corner-cube cavity so that when the adhesive cures and the master is withdrawn from the corner-cube cavity, the reflective surface adheres to the adhesive and remains an integral part of the retroreflector.

Techniques are disclosed to enable manufacture of open-air corner-cube retroreflectors having a corner-cube cavity. The techniques involve additively forming a substrate by way of additive manufacturing technologies such as three-dimensional printing technologies. The techniques further involve optionally machining the additively formed surface of the substrate and replicating a reflective surface in the corner-cube cavity using a master that is coated with a reflective material. An adhesive is applied to the corner-cube cavity so that when the adhesive cures and the master is withdrawn from the corner-cube cavity, the reflective surface adheres to the adhesive and remains an integral part of the retroreflector.

A stage device includes a stage capable of moving in a first direction and a second direction orthogonal to each other, a scale arranged in the stage so as to extend in the first direction, an optical assembly arranged so as to face the scale in at least a part of a movable range of the stage and extending in the second direction, and an interferometer configured to transmit measurement light and reference light to the optical assembly, and receive the measurement light and the reference light returning from the optical assembly. The optical assembly is configured to apply the measurement light from the interferometer to the scale, and return the measurement light returning from the scale and the reference light to the interferometer.

In some examples, a system includes: at least one light capture device; an article of personal protective equipment (PPE) that includes a plurality of retroreflective elements embodied on a surface of the article of PPE in a spatially defined arrangement, each retroreflective element of the plurality of retroreflective elements having at least two different retroreflective properties; a computing device communicatively coupled to the at least one light capture device, wherein the computing device is configured to: receive, from the at least one light capture device, retroreflected light that indicates at least two different retroreflective properties of at least one retroreflective element of the plurality of retroreflective elements; determine, based at least in part on each of the at least two different retroreflective properties, a safety event; and perform at least one operation based at least in part on the safety event.

In some examples, a system includes: at least one light capture device; an article of personal protective equipment (PPE) that includes a plurality of retroreflective elements embodied on a surface of the article of PPE in a spatially defined arrangement, each retroreflective element of the plurality of retroreflective elements having at least two different retroreflective properties; a computing device communicatively coupled to the at least one light capture device, wherein the computing device is configured to: receive, from the at least one light capture device, retroreflected light that indicates at least two different retroreflective properties of at least one retroreflective element of the plurality of retroreflective elements; determine, based at least in part on each of the at least two different retroreflective properties, a safety event; and perform at least one operation based at least in part on the safety event.

An apparatus includes a reflecting element with first, second and third reflecting surfaces, and a receiving element configured to receive a light flux from a light source reflected by the reflecting element. A value of an inner product of a unit normal vector of the first reflecting surface and a unit normal vector of the second reflecting surface, a value of an inner product of the unit normal vector of the first reflecting surface and a unit normal vector of the third reflecting surface, and a value of an inner product of the unit normal vector of the second reflecting surface and the unit normal vector of the third reflecting surface are appropriately set.

An apparatus includes a reflecting element with first, second and third reflecting surfaces, and a receiving element configured to receive a light flux from a light source reflected by the reflecting element. A value of an inner product of a unit normal vector of the first reflecting surface and a unit normal vector of the second reflecting surface, a value of an inner product of the unit normal vector of the first reflecting surface and a unit normal vector of the third reflecting surface, and a value of an inner product of the unit normal vector of the second reflecting surface and the unit normal vector of the third reflecting surface are appropriately set.