57 results about "Linear dispersion" patented technology

The invention discloses a rapid K-space linear frequency sweep laser source. The laser source comprises a semiconductor optical amplifier, two polarization controllers, a dispersion control delay line, a circulator, a tuned filter and an output optical fiber coupler, wherein radiation light emitted from the semiconductor optical amplifier is transmitted to the dispersion control delay line through a polarization controller I; the middle port of the circulator is connected to the tuned filer through a first port of the circulator; returned signals are connected to the optical fiber coupler after passing through a third port of the circulator; one path of the optical fiber coupler outputs frequency sweep laser through a 60% port, and the other path of the optical fiber coupler is connected to the polarization controller II and then returns to a ring laser oscillation cavity; the tuned filter mainly comprises two dispersion elements, namely a grating and a prism, and a rotary polygonal mirror; and the linearity of a wave number space is achieved through combination of linear dispersion of the grating and non-linear dispersion of the prism as well as selection on the angles and directions of the prism. The rapid K-space linear frequency sweep laser source can be used for outputting the rapid K-space linear frequency sweep laser, and can obtain the signals of the linearity of the wave number space directly without calibration when being applied to an OCT (Optical Coherence Tomography) imaging system.

The invention provides a linear dispersion objective lens. Axial dispersion and the wave length approximately form a linear relation within the wavelength range from light F to light C. The linear dispersion objective lens has large dispersion, long working distance and small spherical aberration. The linear dispersion objective lens is composed of a positive lens assembly and a negative lens assembly, wherein the negative lens assembly is close to a needle hole and integrally has negative power, and the positive lens assembly is close to an object and integrally has the positive power. The surface, closest to the object, of the objective lens is a concave face, and the materials of the positive lens assembly and the materials of the negative lens assembly meet the certain dispersion correcting relation. The linear dispersion objective lens can provide large design freedom degree, is used for a spectrum confocal device, effectively improves the whole performance of the device, and is mainly applied to detection of displacement, the transparent element thickness, the micro three-dimensional structure and surface roughness and the like.

The invention discloses a space-time cooperation diversity method of an OFDMA system, which mainly solves the problem of low performance of the system. The method comprises the following steps: 1. the number of terminals participating in cooperation is determined and a linear dispersion code used in cooperation is appointed; 2. subcarriers in the first stage and the second stage are allocated to every terminal; 3. in the first stage of cooperation, LDC code words are sent to other terminals and a receiving terminal by a terminal n on the allocated subcarriers; 4. the LDC code word information sent by the terminal n is received by a terminal m and whether the receiving is correct is checked, if correctly receiving the information of the terminal n, the terminal m reports system to participate in the cooperation, and otherwise, the terminal m does not participate in the cooperation; 5. the terminals participating in the cooperation and LDC code word line components sent by every terminal are determined; 6. in the second period of cooperation, respective cooperation information is sent by the terminals participating in the cooperation to the receiving terminal; and 7. the received information in the first stage and the received information in the second stage are merged and then decoded by the receiving terminal. The invention has the advantages of low bit error rate and is used for cooperation communication in a wireless network.

A magnetic sector for charged particle beam transport that includes a magnetic field profile that achieves a linear dispersion from a collimated beam of charged particles proportional to their mass-energy-to-charge ratio. In one embodiment, the field profile necessary for the linear dispersion is obtained by the use of shaped, highly permeable poles powered by permanent magnets or electromagnetic coils.

The present invention relates to a multiple antenna transmitting / receiving apparatus that performs a hybrid automatic repeat request, and a retransmission method thereof. An initial transmission signal is encoded into the form of an initial transmission matrix and transmitted to the receiving apparatus, the initial transmission matrix corresponding to a linear dispersion code, with a result of error checking performed on the initial transmission signal by the receiving apparatus. When an error is detected in the initial transmission signal, a first retransmission signal is generated by encoding the initial transmission signal in the form of a retransmission matrix and transmitted to the receiving apparatus. The retransmission matrix is formed of constituent elements of the initial transmission matrix but different from the initial transmission matrix, and corresponds to a linear dispersion code having the same capacity and diversity gain as those of the initial transmission matrix.

A spectrometer assembly (10) is disclosed. The assembly includes a light source (11) with a continuous spectrum. A pre-monochromator (2) generates a spectrum with a relatively small linear dispersion from which a spectral portion is selectable, the spectral bandwidth of the spectral portion being smaller than or equal to the bandwidth of the free spectral range of the order in the echelle spectrum. The centre wavelength of the selected spectral interval is measurable with maximum blaze efficiency. The assembly also includes an echelle spectrometer (4) with means for wavelength calibration, an entrance slit (21) at the pre-monochromator (2), an intermediate slit assembly (50) with an intermediate slit (3) and a spatially resolving light detector (5) in the exit plane of the spectrometer for the detection of wavelength spectra.

We introduce a general designing procedure that allows us, for any given photonic crystal slab, to create an appropriate line defect structure that possesses single-mode bands with large bandwidth and low dispersion within the photonic band gap region below the light line. This procedure involves designing a high index dielectric waveguide that is phase matched with the gap of the photonic crystal slab, and embedding the dielectric waveguide as a line defect into a crystal in a specific configuration that is free of edge states within the guiding bandwidth. As an example, we show a single mode line defect waveguide with a bandwidth approaching 13% of the center-band frequency, and with a linear dispersion relation throughout most of the bandwidth.