Abstract: A method for conveying and dropping seedlings based on a device for conveying and positioning a seedling tray of an automatic transplanter, wherein the device for conveying and positioning the seedling tray of the automatic transplanter includes a platform for conveying the seedling tray, a first sensor, a second sensor, a plurality of push rods, and a control system. The platform is configured for conveying the seedling tray to be below seedling picking claws. The push rods are evenly distributed on the platform. The seedling tray is placed between adjacent two of the push rods. The first sensor is mounted close to the seedling picking claws and configured for identifying the seedling tray. The second sensor is mounted on a rack of the platform for conveying the seedling tray and configured for identifying the push rods. The control system controls the platform for conveying the seedling tray.

Abstract: An integrated semiconductor device includes a substrate, semiconductor circuit layers, an insulating material, and an interconnection layer. The semiconductor circuit layers are disposed above the substrate. The semiconductor circuit layers have device portions and isolating portions, and the isolating portions are located among the device portions. The insulating material is disposed on the semiconductor circuit layers, and the interconnection layer is embedded in the insulating material and electrically connected to the semiconductor circuit layers. The isolating portions provide electrical isolation between adjacent device portions. The interconnection layer has circuits embedded in the insulating material on the device portions. The insulating material has isolating structures raised from top surfaces of the circuits on the device portion, and some of the semiconductor circuit layers form at least one heterojunction.

Abstract: An integrated semiconductor device includes a substrate, semiconductor circuit layers, a first insulating layer, a second insulating layer, and an interconnection layer. The semiconductor circuit layers are disposed above the substrate. The semiconductor circuit layers have device portions and isolating portions, and the isolating portions are located among the device portions. The first insulating layer is disposed on the semiconductor circuit layers, and the second insulating layer is disposed on the first insulating layer, and the interconnection layer is disposed on the semiconductor circuit layers. The interconnection layer penetrates the first and second insulating layers to electrically connect the device portions of the semiconductor circuit layers. The second insulating layer or the first and second insulating layers collectively form one or more isolating structures above the isolating portion of the semiconductor circuit layers.

Abstract: A filter and a method of filtering a high frequency electrical signal using photonic components is disclosed. The filter has a serially fiber-coupled laser source, a modulator, a filter, and a photodetector. The electrical signal is applied to the modulator. The modulated light propagates through the filter which is constructed to pass not only a modulated sideband, but also at least a fraction of light at the carrier frequency of the laser. The photodetector detects a signal at the beat frequency between the carrier and sideband signals, after both signals have propagated through the filter. As a result, a separate optical branch for light at the carrier frequency is not required, which considerably simplifies the filter construction and makes it more stable and reliable.

Abstract: A filter and a method of filtering a high frequency electrical signal using photonic components is disclosed. The filter has a serially fiber-coupled laser source, a modulator, a filter, and a photodetector. The electrical signal is applied to the modulator. The modulated light propagates through the filter which is constructed to pass not only a modulated sideband, but also at least a fraction of light at the carrier frequency of the laser. The photodetector detects a signal at the beat frequency between the carrier and sideband signals, after both signals have propagated through the filter. As a result, a separate optical branch for light at the carrier frequency is not required, which considerably simplifies the filter construction and makes it more stable and reliable.

Abstract: There is provided a tunable radio frequency (RF) signal generator comprising: a bi-directional ring laser and a photodetector. The ring laser includes a phase modulator driven by an electrical signal. In use, the modulator imparts a phase shift in dependence on the electrical signal to at least one of a mutually coherent clockwise and counter-clockwise propagating optical signal in the ring laser so as to produce a predetermined difference in the frequency of the clockwise and counter-clockwise propagating signals. The photodetector is optically coupled to an optical output of the ring laser, and in use the photodetector generates a radio frequency signal in dependence on the difference in frequency of the clockwise and counter-clockwise propagating optical signals.