14results about How to "Large tuning range" patented technology

The present invention provides a reverse-driven tunable F-P filter and a preparation method thereof, wherein the filter comprises a static mirror, a moving mirror, a supporting bridge pier, a microbridge, an electrode supporting structure and a top electrode; wherein the supporting bridge pier is prepared on the static mirror, and a cavity is formed between the supporting bridge pier and the static mirror; the moving mirror is located in the cavity, and an F-P resonant cavity is formed between the moving mirror and the static mirror, and a first stopper is prepared on the static mirror to prevent the moving mirror from contacting the static mirror; the microbridge comprises a central part and an edge part, wherein the central part is prepared on the side of the moving mirror facing away from the static mirror, and the central part acts as a bottom electrode for adsorption with the top electrode; the edge part is prepared on the top of the supporting bridge pier, and the electrode supporting structure is supported between the edge part and the top electrode. The present invention can determine the minimum cavity length by using a reverse driving method, and drives the moving mirror in the opposite direction of the static mirror, thereby overcoming the problem of adsorption instability in principle, thereby expanding the spectral detection range by increasing the cavity length tuning range.

The invention relates to the technical field of optical fiber lasers, and proposes an ultra-wideband tunable optical fiber communication light source based on gas stimulated Raman scattering, comprising a 1μm band seed source, an electro-optic modulator, a signal generator, an optical fiber amplifier, a solid-hollow compact coupling device, an optical fiber end cap, a hollow-core optical fiber, a micro gas cavity, a lens, a dichroic mirror, and a methane gas 1μm band tunable pump source. The tuning range covers at least 1024nm-1126nm. Based on the stimulated Raman scattering effect of methane gas, it can be converted into a communication band laser covering the entire S+C+L+U band. Thanks to the Raman characteristics of methane molecules, the output laser has a corresponding narrow line width single spectral line under single wavelength pumping, without accompanying ASE noise amplification, etc., and does not need to be selected through secondary filtering. At the same time, the use of the hollow-core optical fiber ensures that the output laser is only single-mode, and high beam quality can be guaranteed without other operations.

The invention discloses an adjustable MMIC band-pass filter based on a tap inductance technology. The adjustable MMIC band-pass filter comprises a radio frequency input end, a radio frequency output end, a low-pass filter circuit and an adjustable band-pass filter circuit, wherein the low-pass filter circuit and the adjustable band-pass filter circuit are connected between the radio frequency input end and the radio frequency output end in series; the low-pass filter circuit comprises first to third capacitors and an inductor; the adjustable band-pass filter circuit comprises a first network, a second network, a third network, a fourth network, a fifth adjustable capacitor and a sixth adjustable capacitor; one end of the inductor is connected with the radio frequency input end, and the other end of the inductor is coupled with the first network; the first network and the second network are coupled through a fifth adjustable capacitor, the second network and the third network are coupled through a tap inductor, the third network and the fourth network are coupled through a sixth adjustable capacitor, and the fourth network is connected with a radio frequency output end. Compact magnetic coupling is achieved through the tap inductance technology, insertion loss and the chip area are remarkably reduced, and meanwhile the wide tuning range and high harmonic suppression are achieved.

The invention discloses a dual-passband filter with all adjustable center frequency and bandwidth, and aims to provide a band-pass filter with low loss and wide tuning range. According to the technical scheme, each part comprises an input port, an output port, a coupled feeder line, a quarter-wavelength resonator with a variable capacitance diode loaded at the tail end, and a branch resonator with a variable capacitance diode loaded. According to the structure, a coupling line connected with a source and a load is adopted to feed a resonator in a slot coupling mode, the capacitance value of a variable capacitance diode is changed, and finally, the bandwidth and the center frequency are tunable. According to simulation verification, the center frequency of a high pass band of the all-tunable filter disclosed by the invention is continuously adjustable within 2.39-2.61 GHz, and at the moment, the center frequency of a low pass band is kept unchanged at 1.61 GHz and the bandwidth of 120 MHz; the center frequency of the low pass band is continuously adjustable within 1.45 GHz-1. 8GHz, and the center frequency of the high pass band is kept unchanged at 2.51 GHz and the bandwidth of 107MHz; the bandwidth of the high pass band is tunable in the range of 83-132MHz, the insertion loss fluctuates in the range of 1.16-1.45 dB, and at the moment, the center frequency of 1.6 GHz and the bandwidth of 122MHz of the low pass band are kept unchanged. The result shows that the microstrip filter with the tunable center frequency and bandwidth has the advantages of low loss, wide tuning range and wide application range.

This invention discloses a reconfigurable multi-mode ring oscillator, relating to the field of radio frequency integrated circuit design technology. The reconfigurable multi-mode ring oscillator includes multiple delay units and a switching network. The switching network is used to dynamically reconfigure the connection topology of the multiple delay units to switch between three modes. In the first mode, the switching network connects all delay units end-to-end to form a 6-stage ring oscillator. In the second mode, the switching network divides the multiple delay units into two parallel 3-stage sub-loops, and the corresponding core nodes of the two 3-stage sub-loops are coupled to each other through the switching network. In the third mode, the switching network divides the multiple delay units into three parallel 2-stage sub-loops, and the corresponding core nodes of the three 2-stage sub-loops are coupled to each other through the switching network. This provides a novel ring oscillator structure that can increase the tuning range and effectively suppress noise.

The present invention discloses a small-sized wavelength tunable semiconductor laser. It comprises two resonant cavities with different optical lengths, both of which comprise a first reflection surface, a polymer imaging coupler and a second reflection surface, and the two resonant cavities are arranged in a straight line along the same axis, and the second reflection surfaces of the two cavities are connected by a deep-etched waveguide to couple the two resonant cavities; the two polymer imaging couplers, the two second reflection surfaces and the deep-etched waveguide constitute a half-wave coupler, which has wavelength selective loss to achieve the best single-mode characteristics, and at the same time achieves wide-range wavelength tuning through the vernier effect. The present invention achieves small-sized tunability of a channel spacing of 400 GHz to 800 GHz through the small volume feature of the polymer imaging coupler, and does not require the production of gratings, simplifies the process, has a simple and compact structure, and is simple to control by tuning the channel through a single electrode, and has the potential to integrate modulators and photodiodes on a chip, and has the advantages of small size, low cost, and wide-range wavelength tunability.

The present invention relates to the technical field of optical fiber lasers, and proposes a mid-infrared band wide-range precisely tunable optical fiber laser light source, which adopts a widely tunable 1μm laser pump source to obtain an ultra-wideband mid-infrared laser output greater than 1000nm, including a 1μm band tunable pulse seed source, an optical fiber amplifier module, an optical fiber end cap, an end cap coupling device, a hollow-core optical fiber, and a small gas cavity. The 1μm band tunable pulse seed source is a nanosecond pulse laser with a tuning range covering 1024nm-1080nm. Based on the direct tuning of the 1μm band pump source, the wavelength of the 3μm-4μm laser is directly precisely tuned, and the tuning is convenient without adding a seed source. The 1μm band pump source is more likely to obtain high-power laser output, and the hollow-core optical fiber has a high damage threshold, which can effectively improve the mid-infrared output power. The gas Raman laser has a narrow linewidth and the hollow-core optical fiber has a small dispersion, so that the output mid-infrared laser has a narrow linewidth characteristic.

The invention discloses an artificial surface plasmon-based dual-mode oscillator, which comprises a resonance unit, a switching circuit and a differential circuit, and is characterized in that the resonance unit comprises a first metal ring and a second metal ring which are concentric, the inner ring of the first metal ring is connected with a plurality of first metal grid bars facing the second metal ring, and the inner ring of the second metal ring is connected with a plurality of second metal grid bars facing the second metal ring; a plurality of first metal grid bars facing the first metal ring are connected to the outer ring of the first metal ring, a plurality of second metal grid bars facing the first metal ring are connected to the outer ring of the second metal ring, the first metal grid bars and the second metal grid bars are arranged at intervals, a first notch is formed in the first metal ring, a second notch is formed in the position, corresponding to the first notch, of the second metal ring, and a third notch is formed in the position, 180 degrees away from the second notch, of the second metal ring. The two ends of the differential circuit are connected with the two ends of the first gap respectively and used for outputting differential excitation signals, and the two ends of the switching circuit are connected with the two ends of the third gap respectively and used for achieving the switching function, so that the modes of the dual-mode oscillator are switched. The invention has the advantages of wide frequency modulation range and low phase noise, and can be realized on a chip.

This invention provides a wide-tunable single-mode emitting semiconductor laser, comprising: a semiconductor substrate, a first linear ridge waveguide forming a first coupling cavity, and a second linear ridge waveguide forming a second coupling cavity, wherein the first coupling cavity is separated from the second coupling cavity by a gap. The first and second coupling cavities respectively include p-contacts and n-contacts for allowing laser currents I1 and I2 to be injected into the first and second coupling cavities. The first and second coupling cavities respectively include a first heating resistor and a second heating resistor, which are used to heat the first and second coupling cavities respectively when heating currents H1 and H2 are applied to them. The heating resistors are provided for heating the semiconductor substrate of the semiconductor laser to regulate the base temperature of the chip (i.e., the semiconductor substrate). T .

The present application discloses a vertical external cavity surface emitting laser, including a collimating lens; a laser emitting chip located on the first side of the collimating lens, the laser emitting chip including a first electrode with a first light outlet, a first contact layer, an active layer, a second contact layer, and a second electrode with a second light outlet stacked in sequence from bottom to top, and the first light outlet is located on the focal plane of the first side of the collimating lens; a diffraction grating located on the second side of the collimating lens, the first side and the second side facing away from each other; a first top cavity mirror located on the side of the laser emitting chip away from the collimating lens or a second top cavity mirror located in the laser emitting chip. The diffraction grating has a wide tuning range and can provide a relatively flat first-order diffraction efficiency, thereby fully covering the gain spectrum range of the active layer of the laser emitting chip, making the wavelength tuning range the gain spectrum range, the wavelength tuning range is widened, and the vertical external resonant cavity increases the cavity length of the gain resonant cavity and narrows the spectral line width.

The invention discloses a millimeter wave voltage-controlled oscillator and an oscillation mode control method thereof. The voltage-controlled oscillator comprises a first low-frequency oscillator, a second low-frequency oscillator, a first high-frequency oscillator, a second high-frequency oscillator, a first inductor, a second inductor, a third inductor, a fourth inductor and an odd-even mode switch control module. The odd-even mode switch control module can control the first low-frequency oscillator and the second low-frequency oscillator to work in a low-frequency even mode or a low-frequency odd mode, and control the voltage-controlled oscillator to work in a low-frequency even mode or a high-frequency odd mode. By changing the current directions of the first low-frequency oscillator and the second low-frequency oscillator as well as the first high-frequency oscillator and the second high-frequency oscillator, two oscillation modes, namely an even mode and an odd mode, can be respectively realized at high frequency and low frequency by combining with the third circle of inductor, and finally continuous tuning of the four oscillation modes is realized; the tuning range of the voltage-controlled oscillator can be expanded, and the phase noise performance of the voltage-controlled oscillator can be improved.

This invention discloses a distributed LC resonant network Ku-band on-chip tunable low-pass filter. The filter includes an RF signal entering from port 1, flowing sequentially through five high-impedance microstrip lines. These five transmission lines are equivalent to five series inductors at high frequencies. At the nodes of adjacent microstrip lines, four high-impedance microstrip lines and four sets of capacitor switch arrays are connected in parallel. Each high-impedance microstrip line with a series capacitor switch array forms a parallel resonant circuit to ground. Two low-impedance open-circuit microstrip lines are connected in parallel at the input and output ports, respectively. The parasitic capacitance generated at high frequencies is used for impedance matching of the filter. The overall topology is equivalent to an eleventh-order Chebyshev low-pass filter. Compared to existing tunable on-chip low-pass filters, this invention's low-pass filter achieves adjustable cutoff frequency across the entire Ku-band, providing a wide tuning range while ensuring excellent overall performance such as high frequency selectivity, low loss, sufficient out-of-band rejection, and miniaturization.

The application discloses a dual-mode W-waveband voltage-controlled oscillator based on transformer magnetic tuning, which comprises two pairs of cross-coupled MOS transistors, a dual-mode six-coil transformer, a fine-tuning MOS transistor with a tuning switch, a coarse-tuning MOS transistor with a tuning switch and two pairs of output buffer stage MOS transistors; the change of the equivalent inductance value of a resonant cavity is realized by controlling the fine-tuning MOS transistor Msw1 and the fine-tuning MOS transistor Msw2; the fine-tuning MOS transistor Msw1 is turned on in a high-frequency band with small inductance and is turned off in a low-frequency band with large inductance; for fine frequency tuning without a varactor, the resistance of the fine-tuning MOS transistor Msw2 is changed by changing the gate voltage of the fine-tuning MOS transistor Msw2, so that fine tuning of the equivalent inductance is realized; the dual-mode six-coil transformer is used to replace a single-mode three-coil transformer, so that a four-frequency-band W-waveband voltage-controlled oscillator is realized. The application has higher resonant cavity Q value, can realize better phase noise and provides a high-quality local oscillator signal source for a W-waveband signal transceiving front end.