Abstract: A module accommodates multiple superluminescent light emitting diodes, SLEDs, 12r, 12g and 12b. The SLEDs are arranged in an enclosure and output respective light beams to propagate into free space within the enclosure. The individual light beams from the SLED sources are combined into a single beam path within the enclosure using beam combiners 40r-g, 40rg-b. Each beam combiner is realized as a planar optical element, the back side of which is arranged to receive a SLED beam and route it through the optical element to the front side where it is combined with another SLED beam that is incident on and reflected by the front side. The free-space propagating combined beam is output from the module via an optical fiber 42 (or through a window).

Abstract: A monolithic edge-emitting semiconductor diode array chip (100) comprises a one-dimensional array (70) of diode emitters (50), such as laser diodes, superluminescent diodes or semiconductor optical amplifiers. Semiconductor layers are arranged on a conductive substrate (1) and include active region layers (14) arranged between upper and lower cladding layers (12, 16) and separation layers (4, 5) arranged between the conductive substrate (1) and the lower cladding layer (16). The diode emitters (50) are formed by respective ridges (9) that are separated by trenches (25) which are sufficiently deep to penetrate into the separation layers (4, 5). Each diode (50) has its own upper and lower contacts (22, 24) that allow each diode (50) to be independently drivable with a current source driver circuit connected to push a modulated push current through its associated diode and/or a current sink connected to extract a modulated pull current through its associated diode.

Abstract: An edge-emitting semiconductor laser diode chip 15 with mutually opposed front and back end facet mirrors 22, 24. First and second ridges 261, 262 extend between the chip end facets 22, 24 to define first and second waveguides in an active region layer. Low and high slope efficiency laser diodes are thus formed that are independently drivable by respective electrode pairs 211, 231 and 212, 232. The single chip 15 thus incorporates two laser diodes sharing a common heterostructure, one with low slope efficiency optimized for low power operation with good power stability against temperature variations and random threshold current fluctuations in the close-to-threshold power regime, and the other with high slope efficiency optimized for high wall plug efficiency operation at higher output powers when the chip is operating far above threshold.

Abstract: A module accommodates multiple superluminescent light emitting diodes, SLEDs, 12r, 12g and 12b. The SLEDs are arranged in an enclosure and output respective light beams to propagate into free space within the enclosure. The individual light beams from the SLED sources are combined into a single beam path within the enclosure using beam combiners 40r-g, 40rg-b. Each beam combiner is realized as a planar optical element, the back side of which is arranged to receive a SLED beam and route it through the optical element to the front side where it is combined with another SLED beam that is incident on and reflected by the front side. The free-space propagating combined beam is output from the module via an optical fiber 42 (or through a window).

Abstract: An edge-emitting semiconductor laser diode chip 15 with mutually opposed front and back end facet mirrors 22, 24. First and second ridges 261, 262 extend between the chip end facets 22, 24 to define first and second waveguides in an active region layer. Low and high slope efficiency laser diodes are thus formed that are independently drivable by respective electrode pairs 211, 231 and 212, 232. The single chip 15 thus incorporates two laser diodes sharing a common heterostructure, one with low slope efficiency optimized for low power operation with good power stability against temperature variations and random threshold current fluctuations in the close-to-threshold power regime, and the other with high slope efficiency optimized for high wall plug efficiency operation at higher output powers when the chip is operating far above threshold.

Abstract: Superluminescent light emitting diode, SLED, devices and modules are provided. A multi-wavelength SLED device is fabricated by sequentially depositing adjacent epitaxial stacks onto a substrate to form a monolithic chip structure. Each epitaxial stack includes n-type layers, active layers and p-type layers. A ridge is formed in the p-type layers between the end facets of the chip to induce a waveguiding region in the active layers. Different ones of the epitaxial stacks emit at different wavelength ranges. A module is made by packaging one of the above SLED devices with another SLED device, with one inverted relative to the other to form a triangle of emitters as viewed end on, for example a triangle of red, green and blue emitters. The SLED devices and modules may find use in projection, endoscopic, fundus imaging and optical coherence tomography systems.

Abstract: A module accommodates multiple superluminescent light emitting diodes, SLEDs, 12r, 12g and 12b. The SLEDs are arranged in an enclosure and output respective light beams to propagate into free space within the enclosure. The individual light beams from the SLED sources are combined into a single beam path within the enclosure using beam combiners 40r-g, 40rg-b. Each beam combiner is realized as a planar optical element, the back side of which is arranged to receive a SLED beam and route it through the optical element to the front side where it is combined with another SLED beam that is incident on and reflected by the front side. The free-space propagating combined beam is output from the module via an optical fiber 42 (or through a window).

Abstract: A module accommodates multiple superluminescent light emitting diodes, SLEDs, 12r, 12g and 12b. The SLEDs are arranged in an enclosure and output respective light beams to propagate into free space within the enclosure. The individual light beams from the SLED sources are combined into a single beam path within the enclosure using beam combiners 40r-g, 40rg-b. Each beam combiner is realized as a planar optical element, the back side of which is arranged to receive a SLED beam and route it through the optical element to the front side where it is combined with another SLED beam that is incident on and reflected by the front side. The free-space propagating combined beam is output from the module via an optical fiber 42 (or through a window).

Abstract: Superluminescent light emitting diode, SLED, devices and modules are provided. A multi-wavelength SLED device is fabricated by sequentially depositing adjacent epitaxial stacks onto a substrate to form a monolithic chip structure. Each epitaxial stack includes n-type layers, active layers and p-type layers. A ridge is formed in the p-type layers between the end facets of the chip to induce a waveguiding region in the active layers. Different ones of the epitaxial stacks emit at different wavelength ranges. A module is made by packaging one of the above SLED devices with another SLED device, with one inverted relative to the other to form a triangle of emitters as viewed end on, for example a triangle of red, green and blue emitters. The SLED devices and modules may find use in projection, endoscopic, fundus imaging and optical coherence tomography systems.

Abstract: A low power, side-emitting semiconductor laser diode is provided. The laser diode is formed from a semiconductor heterostructure having an active layer sandwiched between an n-type layer and a p-type layer, wherein the active layer forms a gain medium of width W. Front and back reflectors of reflectivity Rf and Rb are arranged on opposing side facets of the semiconductor heterostructure part to form a cavity of length L containing at least a part of the active layer which thus forms the gain medium for the laser diode, the gain medium having an internal loss ?i. To achieve stable, low power operation close to threshold, the laser diode is configured with the following parameter combination: width W: 1 ?m?W?2 ?m; cavity length L: 100 ?m?L?600 ?m; internal loss ?i: 0 cm?1??i?30 cm?1; back reflectivity Rb: 100?Rb?80%; and front reflectivity Rf: 100?Rf?60%.

Abstract: A low power, side-emitting semiconductor laser diode is provided. The laser diode is formed from a semiconductor heterostructure having an active layer sandwiched between an n-type layer and a p-type layer, wherein the active layer forms a gain medium of width W. Front and back reflectors of reflectivity Rf and Rb are arranged on opposing side facets of the semiconductor heterostructure part to form a cavity of length L containing at least a part of the active layer which thus forms the gain medium for the laser diode, the gain medium having an internal loss ?i. To achieve stable, low power operation close to threshold, the laser diode is configured with the following parameter combination: width W: 1 ?m?W?2 ?m; cavity length L: 100 ?m?L?600 ?m; internal loss ?i: 0 cm?1?i?30 cm?1; back reflectivity Rb: 100?Rb?80%; and front reflectivity Rf: 100?Rf?60%.

Abstract: An optical module includes a light source. The light source can be a swept wavelength light source, and optical module includes a wavemeter. The wavemeter includes a wavemeter tap capable of directing a wavemeter portion of light produced by the light source away from a main beam, a wavelength selective filter arranged to receive the wavemeter portion, a first wavemeter detector arranged to measure a transmitted radiation intensity of radiation transmitted through the filter, and a second wavemeter detector arranged to measure a non-transmitted radiation intensity of radiation not transmitted through but reflected by the filter. In addition, an optical coherence tomography apparatus includes the optical module.

Abstract: An optical module includes a light source. The light source can be a swept wavelength light source, and optical module includes a wavemeter. The wavemeter includes a wavemeter tap capable of directing a wavemeter portion of light produced by the light source away from a main beam, a wavelength selective filter arranged to receive the wavemeter portion, a first wavemeter detector arranged to measure a transmitted radiation intensity of radiation transmitted through the filter, and a second wavemeter detector arranged to measure a non-transmitted radiation intensity of radiation not transmitted through but reflected by the filter. In addition, an optical coherence tomography apparatus includes the optical module.

Abstract: A swept wavelength light source is provided, the light source includes a semiconductor gain device operable to provide amplification, an optical retarding device, the retarding device having a block of material, a beam path with a well-defined beam path length being defined for light within the block of material produced by the gain device, a wavelength selector, and the gain device, the retarding device and wavelength selector being mutually arranged on the base so that a resonator is established for light portions emitted by the gain device and selected by wavelength selector; this does not exclude the presence of further elements contributing to the resonator, such as additional mirrors (including resonator end mirrors), lenses, polarization selective elements, other passive optical components, etc.; wherein the beam path in the retarding device is a part of a beam path of the resonator.

Abstract: In accordance with the invention, a display apparatus comprising a light source is provided, said light source comprising at least one superluminescent light emitting diode (SLED), the apparatus further comprising at least one light modulating device arranged in a beam path of a light beam emitted by said light source and operable to emit influenced light upon incidence of said light beam, the light modulating device being operatively connected to an electronic control, the display apparatus further comprising a projection optics arranged in a beam path of said influenced light.

Abstract: A swept wavelength light source is provided, the light source includes a semiconductor gain device operable to provide amplification, an optical retarding device, the retarding device having a block of material, a beam path with a well-defined beam path length being defined for light within the block of material produced by the gain device, a wavelength selector, and the gain device, the retarding device and wavelength selector being mutually arranged on the base so that a resonator is established for light portions emitted by the gain device and selected by wavelength selector; this does not exclude the presence of further elements contributing to the resonator, such as additional mirrors (including resonator end mirrors), lenses, polarization selective elements, other passive optical components, etc.; wherein the beam path in the retarding device is a part of a beam path of the resonator.

Abstract: In accordance with the invention, a light source for display and/or illumination is provided, the light source comprising a heterostructure including semiconductor layers, the heterostructure forming a waveguide between a first end and a second end, the heterostructure comprising a plurality of layers and comprising an optically active zone formed by the plurality of layers, the optically active zone capable of emitting light guided by said waveguide, at least two different radiative transitions being excitable in the optically active an electrical current between a p-side electrode and an n-side electrode, transition energies of said at least two different radiative transitions corresponding to wavelengths in the visible part of the optical spectrum, the light source further comprising means for preventing reflections of light from the waveguide by at least one of said first and second end back into the waveguide, thereby causing the light source to comprise a superluminescent light emitting diode.

Abstract: In accordance with the invention, a light source for display and/or illumination is provided, the light source comprising a heterostructure including semiconductor layers, the heterostructure forming a waveguide between a first end and a second end, the heterostructure comprising a plurality of layers and comprising an optically active zone formed by the plurality of layers, the optically active zone capable of emitting light guided by said waveguide, at least two different radiative transitions being excitable in the optically active an electrical current between a p-side electrode and an n-side electrode, transition energies of said at least two different radiative transitions corresponding to wavelengths in the visible part of the optical spectrum, the light source further comprising means for preventing reflections of light from the waveguide by at least one of said first and second end back into the waveguide, thereby causing the light source to comprise a superluminescent light emitting diode.

Abstract: In accordance with the invention, a display apparatus comprising a light source is provided, said light source comprising at least one superluminescent light emitting diode (SLED), the apparatus further comprising at least one light modulating device arranged in a beam path of a light beam emitted by said light source and operable to emit influenced light upon incidence of said light beam, the light modulating device being operatively connected to an electronic control, the display apparatus further comprising a projection optics arranged in a beam path of said influenced light.

Abstract: In accordance with the invention, a display apparatus including a light source is provided, the light source having at least one superluminescent light emitting diode (SLED), the apparatus further having at least one light modulating device arranged in a beam path of a light beam emitted by the light source and operable to emit influenced light upon incidence of the light beam, the light modulating device being operatively connected to an electronic control, the display apparatus further having a projection optics arranged in a beam path of the influenced light.