摘要:
Integrated optical polarization converter provided with a channel-type waveguide (B) defined by a strip-type structure (S₄) supported by a substrate (S) and consisting of a periodic concatenation of two different part strips having side walls which are at different angles with the plane of the substrate. Preferably, the two part strips then have as cross-sections either a trapezium (EFGH) with Δ₁, Δ₂ ≠ 0) and a rectangle (EFGH with Δ₁ = Δ₂ = 0), or both of them a right-angled trapezium with oblique sides situated opposite one another (EFGH with Δ₁ = 0 and Δ₂ ≠ 0, and EFGH with Δ₁ ≠ 0 and Δ₂ = 0). Oblique and vertical side walls on such a strip-type structure supported by a substrate are fabricated, in the case of suitable crystal orientation, by means of two mutually complementary mask patterns, using etching steps, employing wet-chemical and dry etchants respectively.
摘要:
In accordance with the invention the birefringence induced by compressive strain in silica waveguides on silicon substrates is compensated with a high index patch -- such as silicon nitride layer -- placed adjacent the core. The patch is disposed sufficiently close to the core to optically couple with the transmitted optical mode. The patch is preferably wider than the core to intersect the exponential tail of the transmitted optical mode. Such a high index patch preferentially couples TE polarization modes. By choosing an appropriate length for the patch, both strain and bend birefringence can be compensated.
摘要:
A polarization-independent wavelength demultiplexing apparatus for demultiplexing a light beam of at least one predetermined wavelength, includes a first demultiplexer for demultiplexing the light beam at a predetermined wavelength to obtain a component of the light beam in a first polarization state and second demultiplexer for demultiplexing the light beam at the predetermined wavelength to obtain a component of the light beam in a second polarization state, different from the first polarization state. The first demultiplexer and the second demultiplexer are arranged in a serial manner or in a parallel manner with respect to light transmitted through the demultiplexing structure.
摘要:
Die Erfindung betrifft eine Polarisationsweiche (Polarisationsstrahlteilter), die aus zwei miteinander zu verkoppelnden Wellenleitern (1,2) besteht, zwischen denen in einem Koppelbereich ein weiterer Wellenleiterabschnitt (3) angeordnet ist. Die Anordnung ist derart dimensioniert, daß die Koppelwelle des dritten Wellenleiterabschnittes (3) bei der gewünschten Koppelfrequenz phasensynchron mit den Wellen in den beiden anderen Wellenleitern (1,2) ist. Zudem sind der erste und der zweite Wellenleiter (1,2) jeweils nur über den dritten Wellenleiterabschnitt (3) miteinander verkoppelt. Es ist eine Beschichtung (4) aus einem gut leitenden Material, z.B. einem Metall, vorgesehen, die zumindest den Wellenleiterabschnitt (3) teilweise überdeckt und höchstens den Wellenleiterabschnitt (3) und einen der Wellenleiter (2) im Koppelbereich überdeckt. Durch die metallische Beschichtung wird der effektive Brechungsindex des dritten Wellenleiterabschnittes für die TM-Welle so stark herabgesetzt, daß diese nicht in einen mit Metall beschichteten Wellenleiter überkoppelt. Die Polarisationsweiche spaltet somit beliebig polarisiertes Licht in die TM- und TE-Wellen auf. Eine Anwendung kann eine solche Polarisationsweiche beispielsweise in Überlagerungsempfängern mit Polarisationsdiversity finden.
摘要:
Certain crystalline organic semiconductor compounds, such as 3,4,9,10-perylenetetracarboxylic dianhydride (PTCDA), when deposited by an ultrahigh vacuum process of organic molecular beam deposition, form highly ordered "quasi-epitaxial" films (32) . Due to asymmetries in the molecular crystal structure of such compounds, the ordering of the films results in giant asymmetries in their dielectric properties. Such large dielectric asymmetries permit the construction of a variety of devices, including optical isolators (38) , optically isolated lasers (48) , optical isolated optical amplifiers (64) , polarization-selective photodiodes (76) , and metal-organic-inorganic semiconductor-metal detectors, among others.
摘要:
An optical circuit according to the present invention includes a first beam splitter for splitting a signal light to two polarization lights, first and second optical couplers for coupling the split signal lights and local lights in each, and second and third beam splitters for coupling corresponding polarization lights supplied from the first and second optical couplers. The second and third beam splitters supply output signals to one double-balanced receiver of a polarization diversity receiver.
摘要:
Certain crystalline organic semiconductor compounds, such as 3,4,9,10-perylenetetracarboxylic dianhydride (PTCDA), when deposited by an ultrahigh vacuum process of organic molecular beam deposition, form highly ordered "quasi-epitaxial" films (32) . Due to asymmetries in the molecular crystal structure of such compounds, the ordering of the films results in giant asymmetries in their dielectric properties. Such large dielectric asymmetries permit the construction of a variety of devices, including optical isolators (38) , optically isolated lasers (48) , optical isolated optical amplifiers (64) , polarization-selective photodiodes (76) , and metal-organic-inorganic semiconductor-metal detectors, among others.