Abstract: A method comprising optically detecting optical output states of a plurality of light sources of an optical device over a test interval; for each light source, optically detecting that the output state of the light source has changed from a first optical condition to a second optical condition; for each light source, optically detecting that the output state of the light source has changed from the second optical condition to a third optical condition; for each light source, determining a first time interval representative of the first optical condition; for each light source, determining a second time interval representative of the second optical condition; for each light source, determining a third time interval representative of the third optical condition; determining a test result for the device based on a comparison of the first, second and third time intervals with pre-stored time intervals.

Abstract: A method comprising optically detecting optical output states of a plurality of light sources of an optical device over a test interval; for each light source, optically detecting that the output state of the light source has changed from a first optical condition to a second optical condition; for each light source, optically detecting that the output state of the light source has changed from the second optical condition to a third optical condition; for each light source, determining a first time interval representative of the first optical condition; for each light source, determining a second time interval representative of the second optical condition; for each light source, determining a third time interval representative of the third optical condition; determining a test result for the device based on a comparison of the first, second and third time intervals with pre-stored time intervals.

Abstract: A visible LED light scattering apparatus comprising a substantially hollow spherical cavity including a light entry port arranged to receive visible light from an LED mounted outside the cavity, a light exit port located opposite the entry port and through which the LED light exits the cavity for analysis, and a baffle located in a central region of the cavity in a direct optical path between the entry port and the exit port to interrupt the passage of visible LED light between the entry and exit ports.

Abstract: An apparatus for testing light emitting diodes (LEDs) comprising a chamber which is configured to heat or cool LEDs inside the chamber by ambient heating or cooling of the LEDs and an optical sensing unit configured to sense light emitted by the LEDs while the LEDs are inside the chamber. A method for testing LEDs is also described.

Abstract: A visible LED light scattering apparatus comprising a substantially hollow spherical cavity including a light entry port arranged to receive visible light from an LED mounted outside the cavity, a light exit port located opposite the entry port and through which the LED light exits the cavity for analysis, and a baffle located in a central region of the cavity in a direct optical path between the entry port and the exit port to interrupt the passage of visible LED light between the entry and exit ports.

Abstract: An apparatus for testing light emitting diodes (LEDs) comprising a chamber which is configured to heat or cool LEDs inside the chamber by ambient heating or cooling of the LEDs and an optical sensing unit configured to sense light emitted by the LEDs whilst the LEDs are inside the chamber. A method for testing LEDs is also described.

Abstract: A text fixture (1) comprises apparatus (4) for verifying the color and brightness of light emitted from LEDs (5) of a printed circuit board (3). A base (6) of the fixture (1) supports the printed circuit board (3) during testing. A mounting panel (14) locates ends (15) of a plurality of optical fibers (10) adjacent the LEDs (5) on the printed circuit board (3), and ends (21) of ht optical fibers (10) are terminated in a terminating panel (20) adjacent an image sensing panel (11). The image sensing panel (11) comprises an array of individually addressable light and color sensitive pixels (25) onto which light from the optical fibers (10) is incident. An analysing circuit (12) scans the pixels (25) for determining the brightness values and the tristimulus values of the incident light, and a control circuit (9) compares the tristimulus values and brightness values with reference tristimulus and brightness values for verifying the color and brightness of the light emitted by the respective LEDs (5).

Abstract: A test fixture (1) comprises apparatus (4) for verifying the colour and brightness of light emitted from LEDs (5) of a printed circuit board (3). A base (6) of the fixture (1) supports the printed circuit board (3) during testing. A mounting panel (14) locates ends (15) of a plurality of optical fibres (10) adjacent the LEDs (5) on the printed circuit board (3), and ends (21) of the optical fibres (10) are terminated in a terminating panel (20) adjacent an image sensing panel (11). The image sensing panel (11) comprises an array of individually addressable light and colour sensitive pixels (25) onto which light from the optical fibres (10) is incident. An analysing circuit (12) scans the pixels (25) for determining the brightness values and the tristimulus values of the incident light, and a control circuit (9) compares the tristimulus values and brightness values with reference tristimulus and brightness values for verifying the colour and brightness of the light emitted by the respective LEDs (5).

Abstract: A method for making an optical fiber fusion joint between two dissimilar single mode optical fibers (10,40) where the fibers have different core sizes and/or different refractive index profiles due to different patterns of dopant. One fiber may be a standard step-index communication fiber with a 9 &mgr;m core diameter and a numerical aperture (NA) of about 0.1, and the second fiber may be a dispersion compensating fiber (DCF) with a multiple layer refractive index profile. The second fiber alternatively may have a smaller core and a higher NA, up to about 0.3. A diffused dopant region, with a gradual longitudinal variation in diffusion, is included adjacent to the splice. The diameter of the communications fiber core increases gradually within the diffusion region as the splice joint is approached along this fiber. The diffusion of the various dopants in the second fiber tend to cause its refractive index profile to converge optically to that of the diffused step index communication fiber.