We present results for an heterodyne optical phase-lock loop (OPLL), monolithically integrated on InP with external phase detector and loop filter, which phase locks the integrated laser to an ...external source, for offset frequencies tuneable between 0.6 GHz and 6.1 GHz. The integrated semiconductor laser emits at 1553 nm with 1.1 MHz linewidth, while the external laser has a linewidth less than 150 kHz. To achieve high quality phase locking with lasers of these linewidths, the loop delay has been made less than 1.8 ns. Monolithic integration reduces the optical path delay between the laser and photodiode to less than 20 ps. The electronic part of the OPLL was implemented using a custom-designed feedback circuit with a propagation delay of ~1 ns and an open-loop bandwidth greater than 1 GHz. The heterodyne signal between the locked slave laser and master laser has phase noise below -90 dBc/Hz for frequency offsets greater than 20 kHz and a phase error variance in 10 GHz bandwidth of 0.04 rad2.
This paper presents the results from the first monolithically integrated photonic heterodyne system that allows the two optical sources to be mutually phase locked by locking to an external optical ...reference. High-spectral-purity signals of up to 50 GHz have been demonstrated from this first fabricated device, where the tuning range was limited by losses in the input waveguide. Successful phase locking was accomplished through short signal propagation delay of less than 2 ns achieved by monolithic integration and custom-made fast loop electronics. The approach can be extended to generate signals at >; 1 THz.
In 2019, the Recommendations for the management of patients with lung cancer were published bringing much-needed standardisation of diagnosis and treatment to improve survival of patients with lung ...cancer. Three years after the original Recommendations were published, the update of the Recommendations brings the most innovations in the chapter on systemic treatment of patients with lung cancer. This reflects the remarkable progress made in the field of understanding the oncogenesis and biology of lung cancer and thus the development of new drugs. The burden of lung cancer remains high, as lung cancer is still the most common cause of cancer related death in our country and worldwide. Lung cancer is responsible for one of five cancer-related deaths. Almost one third of patients with lung cancer do not receive any oncological treatment, either because of poor performance status, comorbidities or the extent of the disease. Half of the patients have metastatic disease at diagnosis, resulting in only small improvements in survival despite advances in the treatment of lung cancer patients. These data remind us that if we are to make major shifts in the management of lung cancer patients, we will need to take different approaches. The most promising seems to be the detection of early stages of lung cancer which offers the best treatment results. The Recommendations written here are guidelines for the management of patients with lung cancer. Only with comprehensive multidisciplinary treatment approach, the best outcome from the prognostically unfavourable disease can be offered.
The aim of this retrospective analysis was to investigate VDD mode survival, development of atrial tachyarrhythmias (AT), and long-term atrial sensing performance of VDD pacing systems.
We implanted ...single-lead VDD pacemakers in patients with isolated atrioventricular block and performed a retrospective analysis of 307 patients who had their devices implanted between May 1994 and September 2001. In 39 patients (12.7%), the pacing mode had to be reprogrammed to a single-chamber ventricular pacing mode, mostly due to permanent AT. In 16 of these patients, the atrial sensing safety margin was less than 150%. The atrial sensing safety margin was insufficient, i.e. less than 100% in only seven patients. Although only 12 (3.9%) of the patients had a history of paroxysmal AT at the time of pacemaker implantation, 200 (65%) patients presented with AT during follow-up. The mean AT burden at the last follow-up was 2.5%.
These data illustrate that single-lead VDD pacemakers can be applied without serious complications in a highly selected group of patients. Our main concern is the development of AT in a large part of our population. Over a 10-year period, two thirds of our patients presented with AT.
In this invited paper we review state-of-the-art opto-electronic oscillator technologies with a single optical loop, which represent emerging components for continuous-wave (CW) microwave signal ...generation, available for both electrical and optical carriers. Such a hybrid opto-electronic system uses an external electro-optical modulator, a filter that selects from among the possible oscillation modes, and a long, optical, single-mode fiber in a closed resonator loop. The required resonator quality factor (Q) is proportional to the product of the oscillator's frequency and the fiber's length, which introduces an optical delay with a low loss. The main focus of this paper will be on opto-electronic design issues in order to obtain a low phase noise, a high spectral purity, a high quality factor, a high long-term frequency stability, good robustness, small dimensions, a low power consumption, and a low cost. The key features of the opto-electronic oscillator prototype, where the CW microwave signal is carried to the optical domain using a laser with a 1550-nm wavelength via optical modulation, will be demonstrated.
The opto-electronic oscillator (OEO) is an oscillator with an optical delay line as a resonator. The fact that the increase in frequency of an OEO does not increase its phase noise is an important ...advantage. This enables the generation of low phase-noise signals in the microwave and millimeter wave regions. However, for its more widespread use two problems must be dealt with: frequency drift and multi-mode oscillation. This paper presents recently proposed, novel methods that address the frequency drift and the OEO's multi-mode nature. By implementing a feedback control loop into the OEO it is possible to achieve a frequency drift of 0.05 ppm/K. With an additional phase modulation of the OEO's loop it is possible to increase the side-mode suppression ratio (SMSR) by 5 dB, and a 20-dB improvement in the SMSR is possible with a quality multiplier. The suggested methods operate in the electrical domain, which makes them simple, accessible and low cost.
The opto-electronic oscillator (OEO) is an oscillator with an optical delay line as a resonator. The fact that the increase in frequency of an OEO does not increase its phase noise is an important ...advantage. This enables the generation of low phase-noise signals in the microwave and millimeter wave regions. However, for its more widespread use two problems must be dealt with: frequency drift and multi-mode oscillation. This paper presents recently proposed, novel methods that address the frequency drift and the OEO's multi-mode nature. By implementing a feedback control loop into the OEO it is possible to achieve a frequency drift of 0.05 ppm/K. With an additional phase modulation of the OEO's loop it is possible to increase the side-mode suppression ratio (SMSR) by 5 dB, and a 20-dB improvement in the SMSR is possible with a quality multiplier. The suggested methods operate in the electrical domain, which makes them simple, accessible and low cost.
This paper briefly describes different varactor-loaded multi-subpatch microstrip antenna solutions. Different solutions form kind of an evolutionary sequence, illustrating the process of attaining ...quite complex final antenna design, and describing main properties of individual solutions themselves. The final antenna represents completely frequency and polarization reconfigurable antenna, adjustable by means of varactor diodes, biased by DC voltages. The final design was fabricated and tested in several variations showing extensive frequency and polarization reconfigurability, while maintaining good impedance matching and radiation performances.
Electro-optical synchronization system with femtosecond precision Tratnik, Jurij; Pavlovic, Leon; Batagelj, Bostjan ...
2010 Conference on Optical Fiber Communication (OFC/NFOEC), collocated National Fiber Optic Engineers Conference,
2010-March
Conference Proceeding
A novel system for the RF synchronization is presented. It makes use of standard, commercially-available telecommunication optical components. The added timing jitter of 5 fs RMS has been measured on ...the first experimental tests.
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