A portrait lens configuration for meeting handheld device form factor constraints. First and second meniscus lenses each have a reflective surface to provide internal reflections for transmitting light toward a focal plane. A third lens is positioned between the meniscus lenses and the focal plane. The first lens includes an anterior concave surface having a reflective material extending over a portion thereof. Light received by the first meniscus lens can be transmitted therethrough. The reflective material is positioned along the anterior concave surface to receive light transmitted therethrough and reflected back from the second lens. In an associated method the first meniscus lens is positioned to receive light through a first of two opposing refractive surfaces. After each lens provides an internal reflection, reflected light is transmitted through the second of the two opposing surfaces and then through a bore positioned within the second lens to the third lens.

A portrait lens configuration for meeting handheld device form factor constraints. First and second meniscus lenses each have a reflective surface to provide internal reflections for transmitting light toward a focal plane. A third lens is positioned between the meniscus lenses and the focal plane. The first lens includes an anterior concave surface having a reflective material extending over a portion thereof. Light received by the first meniscus lens can be transmitted therethrough. The reflective material is positioned along the anterior concave surface to receive light transmitted therethrough and reflected back from the second lens. In an associated method the first meniscus lens is positioned to receive light through a first of two opposing refractive surfaces. After each lens provides an internal reflection, reflected light is transmitted through the second of the two opposing surfaces and then through a bore positioned within the second lens to the third lens.

A multi-band/multi-polarization reflective or catadioptric optical system yields differing effective focal lengths (EFLs) per band/polarization. This approach could be used to create an imaging system, for example. In such case, a sensor (imager, spectrometer, diode, etc.) is located at the one or more focal planes. On the other hand, it could also be used to create a projecting system or hybrid projecting and imaging system by locating an emitter such as an LED, laser, etc.) at the image or focal plane. The system employs polarizers and/or dichroic coatings nano patterns to create different focal lengths and/or fields of view using the same mirrors and/or lenses by, for example, including at least one dichroic coating optically in front of at least one additional mirror to separately reflect the different bands or polarizations.

Apparatus and methods for combining beams of amplified radiation are disclosed. A beam combiner has a collimating optic positioned to receive a plurality of coherent radiation beams at a constant angle of incidence with respect to an optical axis of the collimating optic. The respective angles of incidence may also be different in some embodiments. The collimating optic has an optical property that collimates the beams. The optical property may be refractive or reflective, or a combination thereof. A collecting optic may also be provided to direct the plurality of beams to the collimating optic. The beam combiner may be used in a thermal processing apparatus to combine more than two beams of coherent amplified radiation, such as lasers, into a single beam.

An optical element of an embodiment includes an optical element made of a material transparent to light, the optical element including: a back surface facing the front surface; and a connection surface. The front surface includes a recessed surface in a region facing the connection surface. The recessed surface has a point closest to the connection surface as a closest point, and has a first singular point other than the closest point.

Millimeter-wave optical imaging systems and methods. In one example, a mm-wave optical imaging system includes a mm-wave imaging detector located at a focal plane of the optical imaging system, an immersion lens directly coupled to the imaging detector and configured to focus the electromagnetic radiation onto the imaging detector, the immersion lens having a curved first surface and an opposing planar second surface, wherein the focal plane is located on the planar second surface and the imaging detector is directly coupled to the planar second surface, a positive power primary mirror configured to reflect the electromagnetic radiation towards the immersion lens, and a Schmidt aspheric corrector configured to receive and direct the electromagnetic radiation towards the primary mirror, wherein the system aperture stop is located on the Schmidt aspheric corrector.

A modified-Schmidt corrector lens including a first side having a curved surface configured to direct electromagnetic radiation, and a second side having a stepped surface including one or more stepped zones positioned to maintain a substantially constant thickness along a radius of the corrector lens.