摘要:
A high-speed external optical modulator formed on a lithium niobate substrate has a diffused optical waveguide, a surface buffer layer, and electrodes for applying modulating RF energy. The electrodes are electroplated in at least two steps, resulting in a top co-planar waveguide structure lying on a second one. Low driving voltage is achieved through selection of the width, position, and dimension of the lower hot and ground electrodes. The upper ground electrodes and, preferably, also the upper hot electrode, are narrower in width than the corresponding lower electrodes, which helps to provide good velocity matching, good impedance values, and low electrical losses.
摘要:
A semiconductor ridge laser for coupling to a single-mode optical fiber has a ridge with a narrow parallel region, a diverging region, and then a wide parallel region that is adjacent to an output facet. A pump region for the laser may be less than the entire area of the ridge and have a 'T' shape. Preferably, the ridge has a depth of about 350 to 550 nm and the narrow parallel region has a length of more than 0.4 times the overall length of the ridge. The wide parallel region at the output enables the laser to obtain low thermal resistance, which leads to a low operating temperature, a low power density in the laser cavity, and low astigmatism.
摘要:
An optical waveguide device comprises at least one Y-junction integrated on a planar substrate. The junction comprises a first (1), a second (3) and a third (4) optical waveguide extending on the said substrate, and a transition portion (2), in which the second and third waveguides branch from the first waveguide, comprising a truncation (5) of predetermined width. At the position of the truncation, the width of the first waveguide is less than the sum of widths of the second waveguide, the third waveguide and the truncation. The first optical waveguide extends into the transition portion up to the bifurcation with its width essentially constant.
摘要:
The invention relates to a method for electrically connecting a thermoelectric cooler within a package to external terminal pins through at least a connecting lead, said method comprising the steps of:
(a) providing at least a metallised pad at a surface of the thermoelectric cooler; (b) bonding one end of said connecting lead to the said metallised pad of the thermoelectric cooler; (c) bonding the other end of said connecting lead to the external terminal pins, wherein bonding of step (c) uses the parallel gap welding technique. Connecting leads can be either ribbons or wires.
摘要:
A temperature-stabilized optical amplifier (100) comprises at least an erbium-doped waveguide (101) for amplifying optical signals; at least a first and a second pump sources (103, 104) for generating respective pump beams at a first and, respectively, a second pump wavelength (λ 1 , λ 2 ), said first and second pump wavelength being lower and, respectively, higher than 978 nm at an intermediate temperature of a predetermined range of temperature, and being subjected to drift as a consequence of temperature variations; and a pump distribution device (105), optically coupled to said pump sources for receiving said pump beams, and optically coupled to said at least an erbium-doped waveguide for feeding to said at least an erbium-doped waveguide a mixed pump radiation comprising at least a power fraction of each of said pump beams.
摘要:
In a system for monitoring an optical signal carried by a through-waveguide within a planar photonic device, a tap-waveguide (16) is optically coupled to the through-waveguide, such that a portion of the optical signal is diverted into the tap-waveguide. A tap receptacle (20) having a mouth proximate to an exterior surface of the planar photonic device is disposed in the path of the tap-waveguide such that the portion of the optical signal diverted into the tap-waveguide enters the tap receptacle. A light sensor (24) is mounted proximate to the mouth of the tap receptacle for sensing light that has entered the tap receptacle.