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This chapter discusses some of the “super” properties of lasers, superfluids, and superconductors in the context of quantum field theory, including their innate property of spontaneous coherence, which can be seen as the opposite of decoherence.
As the final part of the nonmathematical discussion in this book, this chapter surveys how quantum mechanics plays an important role in existing technology such as the transistors used in computers and nuclear energy, as well as more cutting-edge technologies such as quantum computing, and the strange properties of lasers and superconductors.
While LEDs are the most common emissive device, other emissive devices using conjugated polymers are possible. The use of emissive polymers in devices such as light-emitting electrochemical cells, chemiluminescence cells and light-emitting transistors is described and the different design features needed to optimise their performance discussed. The use of polymers in microcavbities and lasers is discussed. While optically-pumped lasing has been demonstrated, electrically-pumped lasing form organic materials remains to be demonstrated but is not theoretically impossible. The prospects for integrated polymers devices such as optocouplers are also discussed.
To report a single-centre experience in the endoscopic carbon dioxide laser-assisted approach to glomus tympanicum tumours.
Methods
A retrospective case review was conducted of patients diagnosed with class A1 to B1 glomus tympanicum tumours who underwent exclusive transcanal endoscopic carbon dioxide laser surgery.
Results
Seven patients fulfilled the inclusion criteria. All patients (100 per cent) were women, with a mean age of 65.4 years (standard deviation, 13.6). There were five A2 tumours, one A1 tumour and one B1 tumour. One patient presented with a delayed tympanic membrane perforation needing myringoplasty on follow up. There were no substantial post-operative complications. The mean hospitalisation time was 9.5 hours (standard deviation, 9.8). The mean follow-up period was 32.7 months (standard deviation, 13.1), with all cases having resolution of pulsatile tinnitus and no tumour recurrence.
Conclusion
The study provides further evidence on the safety and efficacy of endoscopic carbon dioxide laser surgery as a minimally invasive technique for treating early-stage glomus tympanicum tumours.
To evaluate risk factors for poor prognosis in vocal fold leukoplakia.
Methods
Clinical data were collected for 344 patients with vocal fold leukoplakia who received surgical treatment in our otolaryngology department from October 2010 to June 2019. Univariate and multivariate logistic regression analyses of the relevant factors were conducted.
Results
Among the 344 patients, 98 exhibited recurrence and 30 underwent a malignant change. Multivariate logistic regression analysis showed that size of the lesion (p = 0.03, odds ratio = 2.14), form of the lesion under white light (p < 0.001), surgical method (p < 0.001, odds ratio = 0.28) and pathological type (p < 0.001) were independent factors that affected the recurrence of vocal fold leukoplakia. In both univariate and multivariate analyses, the sole independent risk factor for malignant transformation of vocal fold leukoplakia was pathological type (p < 0.001).
Conclusion
The outlook for vocal fold leukoplakia depends on several clinical factors, especially pathological type. The more severe the pathological type, the more likely it is to recur or become cancerous.
Explore the spectrum of lidar engineering in this one-of-a-kind introduction. For the first time, this multidisciplinary resource covers all the scientific and engineering aspects of atmospheric lidar – including atmospheric science, spectroscopy, lasers and eye safety, classical optics and electro-optics, electrical and mechanical engineering, and software algorithms – in a single comprehensive and authoritative book. Discover up-to-date material not included in any other book, including simple treatments of the lidar crossover range and depolarization in lidar signals, an improved explanation of lidar data inversion algorithms, digital signal processing applications in lidar, and statistical limitations of lidar signal-to-noise ratios. This is an ideal standalone text for students seeking a thorough grounding in lidar, whether through a taught course or self-study.
Nasal obstruction and congestion can occur because of turbinate and septal variations with or without rhinitis. A combined treatment for nasal obstruction and congestion was examined retrospectively in cases where the nasal swell body was addressed with inferior turbinectomy, with or without posterior nasal nerve ablation.
Methods
A 940 nm laser was utilised for contact (nasal swell body, septum and inferior turbinate) and non-contact (posterior nasal nerve) ablation. Total Nasal Symptoms Score, visual analogue scale pain score, complications and procedure location (office vs operating theatre) were recorded.
Results
All 242 patients underwent nasal swell body reduction with inferior turbinate reduction, and 150 had posterior nasal nerve ablation also. No laser complications were observed. An 80 per cent reduction in medication usage was noted. Total Nasal Symptoms Score decreased by 73 per cent; rhinorrhoea and congestion scores decreased by 54 per cent and 81 per cent respectively. Crusting, epistaxis and infections were minimal, and resolved within two weeks.
Conclusion
Nasal swell body with inferior turbinate reduction, with or without posterior nasal nerve ablation, is a new method of treating nasal obstruction and congestion. Laser posterior nasal nerve ablation can be utilised as a complementary tool to deliver anatomical obstruction relief.
Heat from transoral laser microsurgery can cause tissue shrinkage, impacting the surgical margin. This study aimed to compare shrinkage between cold steel and carbon dioxide laser resections of laryngeal lesions.
Methods
A European Laryngological Society type II resection was performed on 10 mm ‘lesions’ marked on both the true and false folds of fresh-frozen human larynxes; specifically, laser resection was performed on the right side and cold steel resection on the left side.
Results
Twenty-eight larynxes were included. Tissue shrinkage was significantly higher in laser resection (35–45 per cent) compared to cold steel resection (8–14 per cent) (p < 0.0001). In most cases, there was no significant difference in shrinkage between true and false fold sites.
Conclusion
This study demonstrates that specimen shrinkage is significantly higher in laser resections. This shrinkage will affect the size of the surgical margin; surgeons and pathologists should be aware of this when considering positive and close margins.
Retraction pockets are collapsed segments of the tympanic membrane. Their formation is associated with a disruption in middle-ear ventilation pathways, leading to the loss of organised collagen of the tympanic membrane. There are several approaches in treating retraction pockets, which aim either to improve ventilation or repair the retraction pockets themselves.
Methods
A review of the literature regarding the classification and associated management of retraction pockets was conducted, using Medline and Cochrane Library databases, with the addition of our institution's experience in undertaking novel techniques.
Results
All the current classification systems fail to guide treatment or prognosticate the disease. Commonly, an initial conservative approach is suggested for early stages, with no clear indication regarding when a surgical solution should be offered. There are conflicting data concerning the effectiveness of these treatments in terms of disease prevention, recurrence and hearing outcomes.
Conclusion
Minimally invasive approaches utilising novel techniques may be key to reducing peri-operative morbidity and improving the overall patient experience.
Suitable for both graduate and senior undergraduate students, this textbook offers a logical progression through the underlying principles and practical applications of nonlinear photonics. Building up from essential physics, general concepts, and fundamental mathematical formulations, it provides a robust introduction to nonlinear optical processes and phenomena, and their practical applications in real-world devices and systems. Over 45 worked problems illustrate key concepts and provide hands-on models for students, and over 160 end-of-chapter exercises supply students with plenty of scope to master the material. Accompanied by a complete solutions manual for instructors, including detailed explanations of each result, and drawing on the author's 35 years of teaching experience, this is the ideal introduction to nonlinear photonics for students in electrical engineering.
Current evidence suggests there is no difference between endoscopic laser surgery and radiotherapy with regards to oncological outcomes of early laryngeal cancer. Patient management may therefore be directed towards voice and quality of life outcomes. This systematic review compares functional outcomes with respect to voice character, swallowing outcomes and quality of life for endoscopic laser surgery versus radiotherapy for T1 and T2 stage laryngeal carcinoma.
Method
Search terminology was designed by both authors and used in Cochrane, PubMed and Web of Science databases. Studies of adult patients treated for primary T1 and T2 laryngeal squamous cell carcinoma utilising one objective (validated) measure of quality of life, swallowing or voice were included.
Results
Initial searches identified 1767 studies. After inclusion and exclusion criteria were applied, 42 studies were identified for full-text review.
Conclusion
This review concluded that neither treatment is clearly advantageous. Future research should be composed of further prospective studies that use a standardised assessment regime to allow valid comparison.
To statistically analyse the hearing thresholds of two cohorts undergoing stapedotomy for otosclerosis with two different prostheses.
Method
A retrospective study was conducted comparing NiTiBOND (n = 53) and Nitinol (n = 38) prostheses.
Results
Average follow-up duration was 4.1 years for NiTiBOND and 4.4 years for Nitinol prostheses. The post-operative air–bone gap was 10 dB or less, indicating clinical success. The p-values for differences between (1) pre- and post-operative values in the NiTiBOND group, (2) pre- and post-operative values in the Nitinol group, (3) pre-operative values and (4) post-operative values in the two groups were: air–bone gap – p < 0.001, p < 0.001, p = 0.631 and p = 0.647; four-frequency bone conduction threshold – p = 0.076, p = 0.129, p < 0.001 and p = 0.005; four-frequency air conduction threshold – p < 0.001, p < 0.001, p = 0.043 and p = 0.041; three-frequency (1, 2 and 4 kHz) bone conduction threshold pre-operatively – p = 0.639, p = 0.495, p = 0.001 and p = 0.01; and air conduction threshold at 4 kHz: – p < 0.001, p < 0.001, p = 0.03 and p = 0.058.
Conclusion
Post-operative audiological outcomes for NiTiBOND and Nitinol were comparable.
Stimulated emission depletion (STED) microscopy is a powerful tool for the study of sub-micron samples, especially in biology. In this article, we show a simple, straightforward method for modeling a STED microscope using Zemax geometrical optics ray tracing principles, while still achieving a realistic spot size. This method is based on scattering models, and while it employs fast ray-tracing simulations, its output behavior is consistent with the real, diffractive behavior of a STED de-excitation spot. The method can be used with Zemax Black Boxes of real objectives for analysis of their performance in a STED setup and open perspective of modeling, tolerancing performance, and then building advanced microscope systems from scratch. In an example setup, we show an analysis method for both XY and Z excitation and de-excitation intensity distributions. This method can simplify the design of custom STED setups by proper modeling of the resolution performance.
We report on a two-arm hybrid high-power laser system (HPLS) able to deliver 2 × 10 PW femtosecond pulses, developed at the Bucharest-Magurele Extreme Light Infrastructure Nuclear Physics (ELI-NP) Facility. A hybrid front-end (FE) based on a Ti:sapphire chirped pulse amplifier and a picosecond optical parametric chirped pulse amplifier based on beta barium borate (BBO) crystals, with a cross-polarized wave (XPW) filter in between, has been developed. It delivers 10 mJ laser pulses, at 10 Hz repetition rate, with more than 70 nm spectral bandwidth and high-intensity contrast, in the range of 1013:1. The high-energy Ti:sapphire amplifier stages of both arms were seeded from this common FE. The final high-energy amplifier, equipped with a 200 mm diameter Ti:sapphire crystal, has been pumped by six 100 J nanosecond frequency doubled Nd:glass lasers, at 1 pulse/min repetition rate. More than 300 J output pulse energy has been obtained by pumping with only 80% of the whole 600 J available pump energy. The compressor has a transmission efficiency of 74% and an output pulse duration of 22.7 fs was measured, thus demonstrating that the dual-arm HPLS has the capacity to generate 10 PW peak power femtosecond pulses. The reported results represent the cornerstone of the ELI-NP 2 × 10 PW femtosecond laser facility, devoted to fundamental and applied nuclear physics research.
In this paper, we report the recent progress on the $1~\text{PW}/0.1~\text{Hz}$ laser beamline of Shanghai Superintense Ultrafast Laser Facility (SULF). The SULF-1 PW laser beamline is based on the double chirped pulse amplification (CPA) scheme, which can generate laser pulses of 50.8 J at 0.1 Hz after the final amplifier; the shot-to-shot energy fluctuation of the amplified pulse is as low as 1.2% (std). After compression, the pulse duration of 29.6 fs is achieved, which can support a maximal peak power of 1 PW. The contrast ratio at $-80~\text{ps}$ before main pulse is measured to be $2.5\times 10^{-11}$. The focused peak intensity is improved by optimizing the angular dispersion in the grating compressor. The maximal focused peak intensity can reach $2.7\times 10^{19}~\text{W}/\text{cm}^{2}$ even with an $f/26.5$ off-axis parabolic mirror. The horizontal and vertical angular pointing fluctuations in 1 h are measured to be 1.89 and $2.45~\unicode[STIX]{x03BC}\text{rad}$, respectively. The moderate repetition rate and the good stability are desirable characteristics for laser–matter interactions. The SULF-1 PW laser beamline is now in the phase of commissioning, and preliminary experiments of particle acceleration and secondary radiation under 300–400 TW/0.1 Hz laser condition have been implemented. The progress on the experiments and the daily stable operation of the laser demonstrate the availability of the SULF-1 PW beamline.
Transoral laser microsurgery for glottic squamous cell carcinoma is the standard of care at many institutions. Repeat transoral laser microsurgery for recurrence may avoid the need for radiotherapy and total laryngectomy. This study aimed to identify oncological and functional outcomes in a cohort of patients who had undergone repeat transoral laser microsurgery procedures.
Method
A retrospective review of prospectively collected data of patients treated with transoral laser microsurgery for carcinoma in situ or tumour stages T1 or T2 glottic cancer, from 2003 to 2018.
Results
Twenty patients were identified. Additional treatment was not needed in 45 per cent of patients. The five-year overall survival rate was 90 per cent. The disease-specific survival rate was 100 per cent. The laryngeal preservation rate was 85 per cent. There was improvement in mean Voice Handicap Index-10 scores following repeat transoral laser microsurgery treatment, when comparing the pre- and post-operative periods (mean scores = 15.5 vs 11.5, p = 0.373).
Conclusion
Repeat transoral laser microsurgery can be an oncologically safe alternative to other salvage therapies for glottic squamous cell carcinoma recurrence, without sacrificing functional outcomes.
Acquired anterior glottic web poses a significant challenge to laryngologists given its propensity to recur following treatment, and there are a wide variety of described techniques.
Methods
A systematic review of the medical literature was undertaken in order to identify all articles pertaining to the management of acquired anterior glottic web.
Results
Thirteen studies meeting the inclusion criteria were identified and analysed. All were retrospective series, with varying surgical techniques and outcome measures. Only two studies reported on the use of topical mitomycin C.
Conclusion
Mucosal graft techniques and keel placement appear to improve success rates, but both carry risks and disadvantages. Based on the available evidence, the use of topical agents such as mitomycin C cannot be recommended in the management of acquired anterior glottic web.
The completion of a laser safety course remains a core surgical curriculum requirement for otolaryngologists training in the UK. This project aimed to develop a comprehensive laser safety course utilising both technical and non-technical skills simulation.
Methods
Otolaryngology trainees and consultants from the West of Scotland Deanery attended a 1-day course comprising lectures, two high-fidelity simulation scenarios and a technical simulation of safe laser use in practice.
Results
The course, and in particular the use of simulation training, received excellent feedback from otolaryngology trainees and consultants who participated. Both simulation scenarios were validated for future use in laser simulation.
Conclusion
The course has been recognised as a laser safety course sufficient for the otolaryngology Certificate of Completion of Training. To the authors’ knowledge, this article represents the first description of using in situ non-technical skills simulation training for teaching laser use in otolaryngology.
The output performances of a bidirectional ring amplifier with twin pulses are demonstrated. Compared to the extraction efficiency of 32% for single-pulse injection, the extraction efficiency of stored energy for twin-pulse injection with bidirectional propagation is increased to 60%. The maximum output energies of the twin pulses are 347 mJ and 351 mJ, and the output energy of a single pulse is only 373 mJ under the same amplifier operating conditions. The experimental results show that the bidirectional ring amplifier with twin pulses can achieve a higher extraction efficiency of stored energy at a lower operating fluence, and has potential applications in high-power and high-energy laser facilities.
To assess published reports of oncological surgical success rates in patients who underwent transoral laser supraglottic surgery and robotic surgery for supraglottic cancer.
Methods
A systematic review of the literature was conducted and a meta-analysis of published data was performed. PubMed, Sage, Medline and Cochrane data sources were investigated. Overall survival rates, disease-specific survival rates, additional treatments and recurrence rates were investigated to determine the success of the surgical procedures.
Results
The meta-analysis included 24 studies; 1617 studies were excluded. There were no statistically significant differences between the transoral laser supraglottic surgery and transoral robotic supraglottic surgery groups in terms of overall survival (77.0 per cent and 82.4 per cent respectively) and disease-specific survival (75.8 per cent and 87.0 per cent respectively). There was recurrence in 164 out of 832 patients (19.7 per cent) in the transoral laser supraglottic surgery group and in only 6 out of 66 patients (9 per cent) in the transoral robotic supraglottic surgery group.
Conclusion
Transoral laser surgery and robotic surgery appear to have comparable and acceptable oncological success rates.