Showing papers on "Insertion loss published in 1985"
TL;DR: In this article, a new optical modulator has been fabricated which uses the recently discovered electroabsorption effect in MQW's and optical pulses 131 ps long were generated when the device was driven with 122 ps electrical pulses.
Abstract: A new optical modulator has been fabricated which uses the recently discovered electroabsorption effect in MQW's. Optical pulses 131 ps long were generated when the device was driven with 122 ps electrical pulses. The input-output characteristics of the device show that it has low insertion loss with reasonable modulation depth and drive voltage.
146 citations
TL;DR: In this article, the authors describe the experimental results of a novel optical filter for a multi/demultiplexer using a diffraction grating and a retroreflector prism.
Abstract: The letter describes the experimental results of a novel optical filter for a multi/demultiplexer using a diffraction grating and a retroreflector prism. A broader passband width, which is proportional to the difference between the prism base length and the input fibre core diameter, is obtained. The minimum insertion loss is 2.2 dB.
63 citations
Patent•
04 Sep 1985TL;DR: In this paper, a biconically tapered optical star coupler is inserted into a protection tube such as hollow glass tube, then the optical fiber bundle is twisted and pulled while it is indirectly heated through the protection tube, thereby to form a twisting, fusing and pulling portion, and both ends of the protected tube are sealed with an adhesive agent to fix the optical fibre bundle to the protection tubes.
Abstract: An optical star coupler having a biconically tapered optical star coupler suspensively inserted in a protection tube and the method for manufacturing the same are disclosed, and the manufacturing method is that an optical fiber bundle is inserted into a protection tube such as hollow glass tube, then the optical fiber bundle is twisted and pulled while it is indirectly heated through the protection tube, thereby to form a twisting, fusing and pulling portion, and both ends of the protection tube are sealed with an adhesive agent to fix the optical fiber bundle to the protection tube. This optical star coupler can be constructed so as to be connected in tandem without any splicing. The optical star coupler of the present invention, naturally in the case of an optical star coupler using multi-mode optical fiber, particularly in the case of one equally divided optical star coupler using single-mode optical fiber, also provides low insertion loss, less power deviation and low manufacturing cost.
59 citations
TL;DR: In this article, the effect of polarization on fiber-waveguide insertion loss is discussed and the first measurements of waveguide-mode position as a function of polarization are presented. And the authors report on coupling arrays of SM fibers in silicon V grooves to waveguides with an average excess loss of 0.3 dB per interface.
Abstract: We report on coupling arrays of SM fibers in silicon V - grooves to waveguides. Arrays with up to 12 fibers have been permanently attached to waveguides with an average excess loss of 0.3 dB per interface. We discuss a subtle, heretofore unreported effect of polarization on fiber-waveguide insertion loss and we describe the first measurements of waveguide-mode position as a function of polarization. In general, the modes of a Ti:LiNbO 3 waveguide peak at different positions. This results in different optimum positions for coupling and thus leads to an unavoidable excess loss when attaching fibers. For low-loss waveguides, we predict a minimum excess loss of 0.25 dB per interface.
51 citations
TL;DR: In this paper, the authors have fabricated the largest integrated optical switch array to date, a square array of 16 interconnected Ti:LiNbO3 directional coupler electro-optical switches.
Abstract: We have fabricated the largest integrated optical switch array to date—a square array of 16 interconnected Ti:LiNbO3 directional coupler electro‐optical switches. The devices operate at ∼11 V and have 4.6–15‐dB fiber‐device‐fiber insertion loss and extinction ratios from −12 to >−35 dB.
49 citations
TL;DR: In this article, a single mode wavelength multiplexer based on diffraction grating and strip waveguides was proposed to minimize the physical spacing between inputs in order to maximize the ratio of channel width to channel separation.
Abstract: We have fabricated and evaluated the first single mode wavelength multiplexer based on a diffraction grating and strip waveguides. The waveguides were employed to minimize the physical spacing between inputs in order to maximize the ratio of channel width to channel separation. The center channel insertion losses for the six channel device were 6.4, 4.9, 6.0, 5.6, 6.8, and 7.8 dB at 1279, 1308, 1338, 1508, 1536, and 1566 nm, respectively. The 1-dB full channel widths averaged 6.0 nm. A matching demultiplexer with multi-mode outputs was also fabricated. The center channel insertion losses were 0.9, 1.1, 1.2, 1.7, 1.8, and 2.1 dB at 1278, 1310, 1337, 1505, 1533, and 1563 nm, respectively. Full 1-dB channel widths ranged from 15 to 11 nm. Out of band rejection exceeded 35 dB.
46 citations
TL;DR: In this paper, a new state-of-polarisation (SOP) control scheme using two Faraday rotators is proposed, which features low optical insertion loss and quick response.
Abstract: A new state-of-polarisation (SOP) control scheme using two Faraday rotators is proposed. It features low optical insertion loss and quick response. Experiment shows that the receiver output is stable regardless of drastic SOP changes in the signal.
45 citations
TL;DR: In this article, a new high-performance surface-acoustic-wave (SAW) filter for use in mobile telephones is presented, from the new filter configuration to the final device operation, a low-loss weighting technique in an interdigital transducer, a new resonant structure, computer simulation procedures, and material properties are treated.
Abstract: A new high-performance surface-acoustic-wave (SAW) filter for use in mobile telephones is presented in this paper. The design for the actual realization of the new filter is examined, from the new filter configuration to the final device operation, A low-loss weighting technique in an interdigital transducer (IDT), a new resonant structure, computer simulation procedures, and material properties are treated. Experimental results with this SAW filter included an 830-MHz center frequency, 3-percent bandwidth, insertion loss of as low as 3.5 ~ 4.0 dB, and 50-dB sidelobe suppression filter.
45 citations
TL;DR: In this article, a low loss Ti:LiNbO3 waveguide electrooptic polarization controller for λ=132 μm was proposed and demonstrated, which provides general polarization transformations, is wavelength tunable, and has a total fiber device fiber insertion loss of 22 dB.
Abstract: We propose and demonstrate a new low loss Ti:LiNbO3 waveguide electro‐optic polarization controller for λ=132 μm The device provides general polarization transformations, is wavelength tunable, and has a total fiber device fiber insertion loss of 22 dB
32 citations
TL;DR: Fused biconical-fiber splitters have been fabricated from dissimilar low-mode-number optical fibers and a tuned condition characterized by low insertion loss and strong optical coupling between modes of the fibers forming the splitter has been demonstrated.
Abstract: Fused biconical-fiber splitters have been fabricated from dissimilar low-mode-number optical fibers. Through selective etching of the cladding diameters of the two fibers forming the splitter, the amount of energy transferred between the fibers can be controlled. A tuned condition characterized by low insertion loss and strong optical coupling between modes of the fibers forming the splitter has been demonstrated. In the detuned condition an asymmetry in the coupling between fibers has been observed.
31 citations
TL;DR: A continuously tunable reflection filter for the 1.2-1.6-microm wavelength range is described, a volume-reflection hologram in dichromated gelatin and exhibits high reflection efficiencies with narrow spectral bandwidth.
Abstract: We describe a continuously tunable reflection filter for the 1.2-1.6-microm wavelength range. The filter is a volume-reflection hologram in dichromated gelatin and exhibits high reflection efficiencies (~95%) with narrow spectral bandwidth (~l% FWHM). These filters have been initially designed for use as position-tuned wavelength demultiplexers or channel-selection switches in multichannel optical-fiber systems. A prototype device has been constructed with an insertion loss between input and output single-mode fibers of <3 dB, with bandwidths Deltalambda((1/2))(FWHM) ~1% over the wavelength band.
TL;DR: In this paper, the fabrication and performance of a stable single-mode transmissive 8×8 star coupler is described, which exhibits very low excess loss (0.13 dB), good coupling uniformity ( 0.73 dB), and low near-end crosstalk (>64 dB).
Abstract: The fabrication and performance of a stable single-mode transmissive 8×8 star coupler is described. The device exhibits very low excess loss (0.13 dB), good coupling uniformity (0.73 dB) and low near-end crosstalk (>64 dB). The star coupler is fabricated from eight lengths of single-mode fibre, by forming 3 dB fused coupling regions between appropriate fibre pairs. A Table of insertion loss measurements is presented, together with graphs showing the wavelength response between 1.2 and 1.7 μm.
TL;DR: In this article, the characteristics and status of magnetostatic waves and devices based on MSW, and initial experimental studies of the application of MSW devices to systems are presented.
Abstract: A need for microwave signal processing components ranging from simple delay lines to broadband, complex analog non-recursive transversal filters has led to the exploration of several solid-state technologies. Bulk acoustic delay lines lack spatial signal tapping and have high insertion loss. Electromagnetic delay lines have high insertion loss, limited signal processing capabilities, and are bulky. Surface acoustic wave (SAW) devices offer excellent signal processing capabilities at VHF/UHF but suffer from excessive loss at microwave frequencies and the requirement for transducers of sub-micron linewidths. However, a signal processing technology based on magnetostatic waves (MSW) propagating on epitaxial yttrium iron garnet (YIG) is emerging to fill microwave signal processing requirements. This paper summarizes the characteristics and status of magnetostatic waves and devices based on MSW, and initial experimental studies of the application of MSW devices to systems, and presents a survey of other potential areas of MSW device applications.
Patent•
NEC1
TL;DR: In this article, an antenna switching circuit is connected between an antenna and the transmitting and receiving sections of the transceiver, so that a filter for removing spurious emission components from a transmitted wave is connected only to the transmitting section.
Abstract: A radio transceiver, improved in that an antenna switching circuit is so connected between an antenna and the transmitting and receiving sections of the transceiver that a filter for removing spurious emission components from a transmitted wave is connected only to the transmitting section of the transceiver, whereby insertion loss of a received wave is avoided.
04 Jun 1985
TL;DR: In this paper, a 1.575 GHz bandpass filter using YIG film grown by liquid phase epitaxy (LPE) was developed, which achieved low insertion loss, high spurious suppression and small temperature drift.
Abstract: A 1.575 GHz bandpass filter using YIG film grown by liquid phase epitaxy (LPE) has been developed. Low insertion loss, high spurious suppression and small temperature drift have been achieved, and the performance of this filter satisfies the requirements for use in a microwave receiver.
TL;DR: In this paper, a truncated parametric array was used as the acoustic source to measure the insertion loss and reflection loss of thin metallic panels, typically 0·45 m square, at normal incidence by using this technique.
TL;DR: In this paper, a W-band non-contiguous diplexer with suspended probe transitions is described, which is suitable for wide-band applications, and the measured insertion loss at the passbands is about 1 dB.
Abstract: A novel design of W-band (75-110 GHz) noncontiguous diplexers is described. The common port of the diplexer is fed by suspended probe transitions which are suitable for wide-band applications. The circuit is printed on a single substrate and easily assembled in a split-block housing. The measured insertion loss at the passbands is about 1 dB. The calculated frequency response of a diplexer is in good agreement with the measurement.
TL;DR: In this paper, the insertion loss procedure yields an attenuation coefficient uncertainty to within five percent, a dynamic range from 4 to 28 dB/mm, and an insertion loss sensitivity of 0.2 dB.
Abstract: Absrmcf-There has been a lack of an accurate procedure for the measurement of an attenuation coefficient for biological tissues at 100 MHz with the scanning laser acoustic microscope (SLAM). The solution to this problem has been approached with two general schemes. One involved a calibrated look-up table, and the other utilized the measurement of insertion loss. For the latter a procedure has been developed and verified using known biological solutions. The insertion loss procedure yields an attenuation coefficient uncertainty to within five percent, a dynamic range from 4 to 28 dB/mm. and an insertion loss sensitivity of 0.2 dB. N IMPORTANT tissue characterization property is the ultrasonic attenuation coefficient, which is the decrease in energy of the sound wave when it propagates through a material. The attenuation includes absorption and scattering. Absorption represents the loss of energy into heat within the specimen. Scattering is a redirection of the energy due to the inhomogeneities of the specimen and includes reflection, refraction, and diffraction. The scanning laser acoustic microscope (SLAM) is a useful tool for providing at 100 MHz, the ultrasonic attenuation coefficient of tissue. A number of techniques have been developed to perform this measurement with the SLAM, and this report details and evaluates these techniques. Details of ultrasonic velocity measurements are found in companion papers [l], [2].
TL;DR: In this article, the authors proposed an optical time switch using LD switch modules and serial delay lines, and reported on its performance for a 256 Mbit/s 4 × 4 switching system.
Abstract: The letter proposes an optical time switch using LD switch modules and serial delay lines, and reports on its performance for a 256 Mbit/s 4 × 4 switching system. It can be constructed with fewer delay lines, and needs neither polarisers nor temperature control. Its total insertion loss is 24.8 dB with a loss margin of 4.0 dB.
TL;DR: In this article, the design and performance of millimeter-wave microstrip/suspended-stripline end-coupled bandpass filters are presented, and an extremely wideband waveguide-to-microstrip transition with an insertion loss of 0.25 dB over the full W-band is also presented.
Abstract: The design and performance of millimeter-wave microstrip/suspended-stripline end-coupled bandpass filters are presented. Filters in Ka-band (26.5 to 40 GHz) and W-band (75 to 110 GHz) using suspended-stripline and microstrip have been designed. Good agreement between the experimental results and those predicted theoretically was observed. Measured passband insertion losses of less than 1 and 0.5 dB have been achieved in W- and Ka-band, respectively. An extremely wideband waveguide-to-microstrip transition with an insertion loss of 0.25 dB over the full W-band is also presented.
Patent•
08 Jul 1985
TL;DR: In this article, an extremely narrow-band bandpass electromagnetic filter is proposed, where the physical dimensions of the waveguide can be further reduced by means of passive coupling means (40), where the cross-section is smaller than in the active sections (30).
Abstract: An extremely narrow-band bandpass electromagnetic filter comprises a waveguide (1) dimensioned below cutoff and having two or more active sections (30) each containing a dieletric resonator (6). The number of resonators (6) corresponds to the number of poles of filtering. The physical dimensions of the waveguide (1) can advantageously be further reduced by means of passive coupling means (40), where the waveguide (1) cross-section is smaller than in the active sections (30). Each passive coupling means (40) inductively couples adjacent active sections (30). Mode suppression rods (10) electrically connect opposing waveguide walls (2, 3) midway between each pair of adjacent dielectric resonators (6). Preferred embodiments are illustrated, in which the resonators (6) are transversely oriented within the waveguide (1). Electromagnetic energy travels within the waveguide (1) in a single TE10 evanescent mode (TE01delta within the resonators (6)). Dielectric tuning means (9) are generally aligned along the principal axis of each resonator (6). A number of such filters, exhibiting extremely narrow bandwidth, low insertion loss, and high Q, have been successfully built.
TL;DR: In this paper, lowvoltage driving and high-speed modulations of InGaAsP/InP electroabsorption modulators with strip-loaded planar waveguide have been described.
Abstract: Low-voltage driving and high-speed modulations of InGaAsP/InP electroabsorption modulators with strip-loaded planar waveguide have been described. The modulators were fabricated from VPE-grown InGaAsP/InP double-heterostructure wafers. For ?=1.55 ?m incident light an extinction ratio of 20 dB was achieved with an applied voltage of ~?6 V. The insertion loss was 9.6 dB. The calibrated 3 dB bandwidth was 1.6 GHz.
TL;DR: In this paper, a novel optical isolator consisting of an yttrium-iron-garnet (YIG) sphere and two PANDA-fibre polarisers is reported.
Abstract: A novel optical isolator consisting of an yttrium-iron-garnet (YIG) sphere and two PANDA-fibre polarisers is reported. The YIG sphere functions not only as a Faraday rotator but also as an efficient coupling lens. The extinction ratio of the PANDA-fibre polariser was 37 dB when the 3 m-long fibre was coiled by the diameter D = 21 cm. The isolation ratio was 34.7 dB at 1.3 ?m wavelength with the insertion loss of 4.1 dB through the PANDA-fibre polariser to the analyser.
TL;DR: In this paper, a waveguide diplexer is introduced where optimised low-insertion-loss metal insert filters are directly integrated in the E-planes of the T-junction arms.
Abstract: A waveguide diplexer is introduced where optimised low-insertion-loss metal insert filters are directly integrated in the E-planes of the T-junction arms. The filters are designed by the exact method of field expansion into suitable eigenmodes which takes the influences of higher-order-mode interaction and finite thickness of the inserts into account. Computer optimised design data are given which provide a metaletching technique for reliable low-cost production. Measured minimum passband insertion losses of an R120-waveguide diplexer prototype are about 0.8 dB at 10.4 GHz, and 0.5 dB at 11.2 GHz. The stopband attenuation at 10.8 GHz is about 48 dB.
Patent•
08 Jul 1985TL;DR: In this article, an extremely narrow-band band-pass electromagnetic filter is proposed, where the waveguide cross-section is smaller in the active sections than in the passive sections.
Abstract: An extremely narrow-band bandpass electromagnetic filter comprises a waveguide (1) dimensioned below cutoff and having two or more active sections (30) each containing a dielectric resonator (6). The number of resonators (6) corresponds to the number of poles of filtering. The physical dimensions of the waveguide (1) can advantageously be further reduced by means of passive coupling means (40), where the waveguide (1) cross-section is smaller than in the active sections (30). Each passive coupling means (40) inductively couples adjacent active sections (30). Mode suppression rods (10) electrically connect opposing waveguide walls (2, 3) midway between each pair of adjacent dielectric resonators (6). Preferred embodiments are illustrated, in which the resonators (6) are tranversely oriented within the waveguide (1). Electromagnetic energy travels within the waveguide (1) in a single TE10 evanescent mode (TE01δ within the resonators (6)). Dielectric tuning means (9) are generally aligned along the principal axis of each resonator (6). A number of such filters, exhibiting extremely narrow bandwidth, low insertion loss, and high Q, have been successfully built.
TL;DR: In this article, the insertion loss and the noise temperature contribution were measured at 4.7 K. The insertion loss was investigated as a function of out-of-band power (up to 1 watt) and temperature.
Abstract: Superconducting Nb 0.45 >Ti 0.55 and Pb electroplated on Cu bandpass microwave filters have been constructed to investigate their low loss properties at 4.7 K. An interdigital stripline filter configuration was selected as the optimum structure for future applications. The filter was designed to operate at 8.45 GHz with an equal ripple bandwidth of 0.15 GHz. The insertion loss and the noise temperature contribution were measured at 4.7 K. In addition, the insertion loss was studied as a function of out-of-band power (up to 1 watt) and temperature (4.7 K to T c ). Results on an OFHC Cu filter are included for comparison.
TL;DR: In this paper, a GaAs second-order switched-capacitor bandpass filter has been fabricated with an insertion loss of between 3 dB and 15 dB and a center frequency accuracy of 90-98%.
Abstract: A GaAs second-order switched-capacitor bandpass filter has been fabricated. Operation with clock frequencies up to 100 MHz and centre frequencies up to 4 MHz has been achieved, with an insertion loss of between 3 dB and 15 dB and a centre frequency accuracy of 90-98%.