The American Society for Clinical Pathology 2022 Vacancy Survey of medical laboratories in the United States

OBJECTIVES

To determine the extent and distribution of laboratory workforce shortages within the nation's medical laboratories.

METHODS

The Vacancy Survey was conducted through collaboration between the American Society for Clinical Pathology (ASCP) Institute for Science, Technology and Public Policy in Washington, DC, and the Evaluation, Measurement, and Assessment Department and ASCP Board of Certification in Chicago, IL. Data were collected through an internet survey distributed to individuals who were able to report on staffing and certifications for their laboratories.

RESULTS

Results of the ASCP 2022 Vacancy Survey show increased overall vacancy rates for laboratory positions in all departments compared with 2020. Overall retirement rates for laboratory professionals increased across most departments.

CONCLUSIONS

Current Vacancy Survey data show continued increases in the numbers of laboratory vacancies and retirements as well as changes in certification requirements, with trends amplified during the pandemic continuing into the present. Qualitative analysis results showed that there is an urgent need to focus not only on recruitment but-equally important-on retention of laboratory professionals.

Examining the role of diversity, equity, and inclusion in mitigating workforce burnout in laboratory medicine

OBJECTIVES

The clinical laboratory workforce plays a crucial role in health care delivery, yet little is known about the unique pressures and challenges this workforce faces. The objective of this study was to identify factors that contribute to burnout, discrimination, exclusion, and inequity in pathology and laboratory medicine.

METHODS

A nationwide survey was conducted in 2 phases. In phase 1, 2391 laboratory professionals were surveyed over a 1-week period about their experiences with burnout, discrimination, and work-related stress. In phase 2, the survey was extended to 1 month and questions were added to elicit more detailed information about diversity, equity, and inclusion (DEI) as well as wellness.

RESULTS

Results showed a high prevalence of burnout, discrimination, and stress among laboratory professionals, with significant differences among certain demographic groups. Women, Black, indigenous, or people of color individuals and those with disabilities reported higher rates of discrimination. The study also showed a need for mentorship and resources to address educational barriers.

CONCLUSIONS

Findings from this study highlight the urgent need for interventions to address burnout, discrimination, exclusion, and inequity in the laboratory workforce. Initiatives to increase workforce diversity, promote mentorship and diversity training programs, and improve recognition of the laboratory workforce are recommended. The results underscore the pressing need to addressing the challenges and apprehensions laboratory professionals face, including enhancing recognition of their role in patient care, tackling systemic problems related to discrimination and equity, and enhancing the provision of support and resources for managing burnout and fostering well-being.

The American Society for Clinical Pathology’s 2021 Wage Survey of Medical Laboratories in the United States

Objectives

To inform the pathology and laboratory field of the most recent national wage data. Historically, the results of this biennial survey have served as a basis for additional research on laboratory recruitment, retention, education, marketing, certification, and advocacy.

Methods

The 2021 Wage Survey was conducted through collaboration between the American Society for Clinical Pathology (ASCP) Institute of Science, Technology, and Policy in Washington, DC, and the ASCP Board of Certification in Chicago, IL.

Results

Compared with 2019, results show that mean hourly wage for staff-level personnel increased for only two occupations—cytologist and medical laboratory scientist/medical technologist/clinical laboratory scientist—after adjusting for inflation. Geographically, laboratory professionals from urban areas continue to earn more than their rural counterparts. Most respondents reported no change in their salaries during the coronavirus disease 2019 pandemic.

Conclusions

The pandemic had a significant effect on staffing, workload, and work-life balance of many laboratory professionals. Even with the salary increases reported from the results of this survey, it is evident that the increases have not kept up with the current inflation. Focus on visibility, recruitment and retention, and diversity are essential to develop long- and short-term solutions.

The American Society for Clinical Pathology 2020 Vacancy Survey of Medical Laboratories in the United States

OBJECTIVES

To determine the extent and distribution of workforce shortages within the nation's medical laboratories.

METHODS

The survey was conducted through collaboration between the American Society for Clinical Pathology Institute for Science, Technology, and Public Policy in Washington, DC, and the Evaluation, Measurement, and Assessment Department and Board of Certification in Chicago, IL. Data were collected via an internet survey distributed to individuals who were able to report on staffing and certifications for their laboratories.

RESULTS

The coronavirus disease 2019 (COVID-19) pandemic disrupted the staffing of clinical laboratories and the stream of incoming graduates entering the workforce. Results show decreased vacancy rates for the majority of laboratory positions across all departments surveyed. The overall anticipated retirement rates continue to decline, which suggests that the field has already lost personnel with vast amounts of experience.

CONCLUSIONS

Addressing the current and future needs of the laboratory workforce requires a collective effort by numerous groups of stakeholders at all levels, including the laboratory employers, laboratory training programs, health care executives/hospital administrators, and professional organizations. The time is now to address the future shortage of laboratory professionals and to create a resilient clinical laboratory professional workforce.

American Society for Clinical Pathology's 2019 Wage Survey of Medical Laboratories in the United States

OBJECTIVES

To inform the pathology and laboratory field of the most recent national wage data. Historically, the results of this biennial survey have served as a basis for additional research on laboratory recruitment, retention, education, marketing, certification, and advocacy.

METHODS

The 2019 Wage Survey was conducted through collaboration of the American Society for Clinical Pathology (ASCP) Institute of Science, Technology, and Policy in Washington, DC, and the ASCP Board of Certification in Chicago, Illinois.

RESULTS

Compared with 2017, results show an overall increase in salaries for most laboratory occupations surveyed except cytogenetic technologists, laboratory information systems personnel, and performance improvement or quality assurance personnel. Geographically, laboratory professionals from urban areas earned more than their rural counterparts.

CONCLUSIONS

As retirement rates continue to increase, the field needs to intensify its efforts on recruiting the next generation of laboratory personnel. To do so, the report urged the field to highlight advocacy for better salaries for laboratory personnel at the local and national levels when developing recruitment and retention strategies.

Revised Reporting (Issuing Addenda and Amendments) in Pathology

OBJECTIVES

The purpose of this study was to align the current experiences and best practices in revised reporting (issuing of addenda and amendments) in pathology. Pathology specialties explored in the survey include anatomic pathology, surgical pathology, cytopathology, and hematopathology.

METHODS

The study used a cross-sectional design in which an online revised reporting survey was deployed to a large national sample represented by pathologists, pathology residents, pathology fellows, pathology managers, and laboratory directors.

RESULTS

Qualitative and quantitative results from this survey highlight significant variation in standards for creating, issuing, and tracking quality indicators related to addenda and amendments. The most notable findings were a lack of standardization and the potential for widespread adoption of revised reporting best practices within and between pathology services.

CONCLUSIONS

Survey insight provides the potential for improving patient safety outcomes, engaging with consumers of our reports, providing a current state view of revised reporting, and assessing the attitudes of pathologists and laboratory professionals on how their individual approaches and team-based workflows achieve revised reports. The data generated from this survey will provide patient safety opportunities associated with accurate pathology reporting and will encourage further development of optimal pathology revised reporting guidelines.

Diagnostic Accuracy & Pathology Revised Reports: Evidence-Based Guideline Development

Introduction/Objective

Diagnostic errors in pathology may have adverse impact on patient outcomes and are often rectified through revised reports (RR). Improving patient outcomes with accurate RR is a tangible yet challenging benefit to assuring continuous quality improvement (CQI). Assessment and elevation of RR optimization requires counterbalance of workflow complexity in the diagnostic reporting domain. Implications inform best-practice guidelines for pathology RR and exemplify improved patient outcomes by driving down negative impacts from diagnostic errors.

Methods

A “Survey for RR in Pathology: Reality & Best Practices” was sent via email to relevant stakeholders. The 8-item survey was designed by the National Pathology Quality Registry team & ASCP’s Institute for Science, Technology & Policy. The model included quantitative and qualitative feedback to probe current experiences with RR. The survey was open April 1-30, 2019, via Key Survey and used snowball sampling.

Results

Key results illuminate necessity for RR standardization. Survey findings represent 172 respondents. Ninety- two percent of respondents indicated report accuracy as a major indication for optimizing RR practices & positively impacting patient care. Pathology practices assure appropriate RR by notifying a care provider when a change in diagnosis necessitates RR (89%) & 86% of respondents indicate delineation of RR types (e.g. addenda, amendment). Still 54% of respondents see inappropriate RR use with lack of notification to care providers and 48% indicate no delineation of RR types. This balance-counterbalance highlights deviations from optimized RR and a need for guidelines. Effects on patient care or impact to a patient’s treatment plan was indicated by 43% who affirmed stratification of diagnostic discrepancies as major vs. minor. Solely focusing on changes in diagnosis (benign vs. malignant) was heralded by 19% of respondents as a reason to categorize diagnostic discrepancies. Forty-two percent of respondents indicate data-driven CQI in the RR domain.

Conclusion

Identified RR practice gaps decrease diagnostic accuracy, confirming the need for optimal RR guidelines. RR guidelines should focus on standardized nomenclature; active dialogue between laboratory team & clinical care partners; streamlined workflows to assure accuracy; & valuing transparency to derive improved patient outcomes based on high-quality diagnostic pathology RR.

The American Society for Clinical Pathology's Job Satisfaction, Well-Being, and Burnout Survey of Pathologists

OBJECTIVES

To examine job satisfaction, well-being, job stress, and burnout among pathologists.

METHODS

The study utilized a cross-sectional survey design. The survey was administered online via the American Society for Clinical Pathology's (ASCP's) survey tool to elicit information about job satisfaction, well-being, job stress, and burnout among pathologists.

RESULTS

Job satisfaction is high and well-being is rated fair to good by most respondents. However, feelings of anxiety or worry about work, high levels of stress, and burnout are prevalent among pathologists. The main contributing factor to job stress, burnout, and work-life balance is quantity of workload.

CONCLUSIONS

Creating targeted interventions based on the results of this survey may help improve the type and quality of wellness programs for pathologists. Trust among team members, managers and clinicians, and institutions can help reduce stress and increase collaboration, engagement, and motivation.

The American Society for Clinical Pathology's Job Satisfaction, Well-Being, and Burnout Survey of Laboratory Professionals

OBJECTIVES

To examine job satisfaction, well-being, job stress, and burnout among laboratory professionals.

METHODS

The study utilized a cross-sectional survey design. The survey was administered online via the American Society for Clinical Pathology's survey tool, to elicit information about job satisfaction, well-being, job stress, and burnout among medical laboratory professionals.

RESULTS

Although this survey shows high job satisfaction among respondents, overall job-related stress is high and burnout is prevalent. The majority of the respondents rated their work-life balance as "fair." The main contributing factors to job stress, burnout, and work-life balance are quantity of workload and understaffing.

CONCLUSIONS

Based on the results of this survey, creating targeted interventions may help improve the quality of well-being programs for laboratory professionals. A comprehensive wellness program developed at the institutional, local, and national levels may improve morale and alleviate the recruitment and retention challenges faced by medical laboratory professionals.

Job Stress, Burnout, Work-Life Balance, Well-Being, and Job Satisfaction Among Pathology Residents and Fellows

OBJECTIVES

The study explored job stress, burnout, work-life balance, well-being, and job satisfaction among pathology residents and fellows. The aims were to examine the prevalence and sources of stress and burnout, as well as identify resources to promote work-life balance and well-being and prevent burnout.

METHODS

The study used a cross-sectional survey deployed online to a large national sample of pathology residents and fellows.

RESULTS

Job stress and burnout were prevalent, with more than a third of the respondents reporting that they were currently experiencing burnout. The respondents, particularly residents, were struggling with academics, and higher percentages were struggling with work-life balance and emotional well-being. Overall, the majority of respondents who rated their work-life balance indicated that it was poor or fair. Among the factors contributing to job stress and burnout and detracting from work-life balance, workload was the leading factor.

CONCLUSIONS

The factors contributing to job stress and burnout included organizational factors such as workload, value, and aspects of the learning environment, as well as personal factors such as work-life integration. One of the overarching implications is the need to address a range of interdependent considerations in designing resources to reduce job stress, promote work-life balance, and prevent burnout.

Terahertz photonic integrated circuit for frequency tuning and power modulation

The quantum cascade laser is a powerful solid-state source of terahertz-frequency radiation. However, integrating multiple photonic functions into a monolithic platform in this frequency range is non-trivial due to the scaling of photonic structures for the long terahertz wavelengths and the low frequency tuning coefficients of the quantum cascade lasers. Here, we have designed a simple terahertz-frequency photonic integrated circuit by coupling a racetrack resonator with a ridge laser in the longitudinal direction to design a notch filter. The transmission properties of this filter structure are dependent on the phase matching and losses in the coupled racetrack and results in a comb of stopband frequencies. We have optimized the comb separation by carefully selecting the cavity dimensions of the racetrack resonator to suppress longitudinal modes in the ridge laser enabling single-mode emission. The emission frequencies and output power from laser are controlled through appropriate control of drive currents to the ridge and the racetrack resonator. The emission frequency is electrically tuned over ∼81 GHz exploiting Stark shift of the gain as a function of drive current at the ridge laser, coinciding with an output power variation of ∼27% of the peak power (at a heat sink temperature of 50 K). The output power from the ridge also varied by ∼30% and the frequency was tuned by a further 10 GHz when the driving conditions at the ridge laser are invariant and the current at the racetrack resonator was varied. To our best knowledge, this is the first report of a frequency engineering, tuning and power modulation of terahertz-frequency quantum cascade lasers using a photonic integrated circuit.

High-speed modulation of a terahertz quantum cascade laser by coherent acoustic phonon pulses

The fast modulation of lasers is a fundamental requirement for applications in optical communications, high-resolution spectroscopy and metrology. In the terahertz-frequency range, the quantum-cascade laser (QCL) is a high-power source with the potential for high-frequency modulation. However, conventional electronic modulation is limited fundamentally by parasitic device impedance, and so alternative physical processes must be exploited to modulate the QCL gain on ultrafast timescales. Here, we demonstrate an alternative mechanism to modulate the emission from a QCL device, whereby optically-generated acoustic phonon pulses are used to perturb the QCL bandstructure, enabling fast amplitude modulation that can be controlled using the QCL drive current or strain pulse amplitude, to a maximum modulation depth of 6% in our experiment. We show that this modulation can be explained using perturbation theory analysis. While the modulation rise-time was limited to ~800 ps by our measurement system, theoretical considerations suggest considerably faster modulation could be possible.

The typical electronic modulation of terahertz quantum cascade lasers is fundamentally limited at fast timescales by device properties. Here the authors propose and study an alternative, acoustic mechanism for modulating such THz QCLs at high speed.

Attitudes and referral practices for pre-exposure prophylaxis (PrEP) among HIV rapid testers and case managers in Philadelphia: A mixed methods study

Objective

Adoption of pre-exposure prophylaxis (PrEP) to prevent HIV infection has been slow. The purpose of this study was to evaluate knowledge, attitudes and referral practices for PrEP among non-prescribing providers, who may play key role.

Methods

We performed a cross-sectional survey on PrEP knowledge, attitudes, and referral practices among 66 non-prescribing HIV prevention providers (1st August to 31st December, 2016), in Philadelphia, followed by qualitative interviews with 12 of them (5th April to 10th May, 2017).

Results

Participants had a mean age of 36 years, with 62% females. Majority were HIV case managers and rapid testers. For half of the respondents, PrEP eligibility screening was part of rapid HIV testing at their organization, 40% never had PrEP training and only 27% indicated personally screening clients for eligibility. Qualitative data revealed that participants held positive attitudes about PrEP and perceived organizational support, but had concerns about potential negative impacts and barriers to routine HIV screening.

Conclusion

Results highlight the importance of training non-prescribing HIV prevention providers about PrEP, addressing their concerns, and incorporating PrEP screening and referral into routine HIV testing.

Giant optical nonlinearity interferences in quantum structures

Second-order optical nonlinearities can be greatly enhanced by orders of magnitude in resonantly excited nanostructures. These resonant nonlinearities continually attract attention, particularly in newly discovered materials. However, they are frequently not as heightened as currently predicted, limiting their exploitation in nanostructured nonlinear optics. Here, we present a clear-cut theoretical and experimental demonstration that the second-order nonlinear susceptibility can vary by orders of magnitude as a result of giant destructive, as well as constructive, interference effects in complex systems. Using terahertz quantum cascade lasers as a model source to investigate interband and intersubband nonlinearities, we show that these giant interferences are a result of an unexpected interplay of the second-order nonlinear contributions of multiple light and heavy hole states. As well as of importance to understand and engineer the resonant optical properties of nanostructures, this advanced framework can be used as a novel, sensitive tool to elucidate the band structure properties of complex materials.

The American Society for Clinical Pathology's 2018 Vacancy Survey of Medical Laboratories in the United States

OBJECTIVES

To determine the extent and distribution of workforce shortages within the nation's medical laboratories.

METHODS

The survey was conducted through collaboration between the American Society for Clinical Pathology's Institute of Science, Technology, and Policy in Washington, DC, and the Evaluation, Measurement, and Assessment Department and Board of Certification in Chicago, IL. Data were collected via an internet survey distributed to individuals who were able to report on staffing and certifications for their laboratories.

RESULTS

Results show increased vacancy rates for laboratory positions across all departments surveyed. The overall retirement rates are at its lowest, suggesting that the field has already experienced loss of personnel with a vast amount of experience.

CONCLUSIONS

Focus on retention of qualified and certified laboratory professionals would be crucial factors in addressing the needs of the laboratory workforce. The field also needs to intensify its efforts on recruiting the next generation of laboratory personnel.

Detection sensitivity of laser feedback interferometry using a terahertz quantum cascade laser

We report on the high detection sensitivity of a laser feedback interferometry scheme based on a terahertz frequency quantum cascade laser (QCL). We show that variations on the laser voltage induced by optical feedback to the laser can be resolved with the reinjection of powers as low as ∼-125  dB of the emitted power. Our measurements demonstrate a noise equivalent power of ∼1.4  pW/√Hz, although, after accounting for the reinjection losses, we estimate that this corresponds to only ∼1  fW/√Hz being coupled to the QCL active region.

The American Society for Clinical Pathology's 2017 Wage Survey of Medical Laboratories in the United States

Objectives

To inform the pathology and laboratory field of the most recent national wage data. Historically, the results of this biennial survey have served as a basis for additional research on laboratory recruitment, retention, education, marketing, certification, and advocacy.

Methods

The 2017 Wage Survey was conducted through collaboration between the American Society for Clinical Pathology's (ASCP's) Institute of Science, Technology, and Policy in Washington, DC, and the ASCP Board of Certification in Chicago, IL.

Results

Compared with 2015, results show an overall increase in salaries for most of the laboratory occupations surveyed except histotechnologists and pathologists' assistants. Geographically, laboratory professionals from urban areas earn more than their rural counterparts.

Conclusions

Survey results encourage laboratory professionals to be actively engaged in advocating for the profession in the workforce and educational training programs. Awareness of the career opportunities and value of the profession is needed to strengthen the future of the field.

Ultrafast switch-on dynamics of frequency-tuneable semiconductor lasers

Single-mode frequency-tuneable semiconductor lasers based on monolithic integration of multiple cavity sections are important components, widely used in optical communications, photonic integrated circuits and other optical technologies. To date, investigations of the ultrafast switching processes in such lasers, essential to reduce frequency cross-talk, have been restricted to the observation of intensity switching over nanosecond-timescales. Here, we report coherent measurements of the ultrafast switch-on dynamics, mode competition and frequency selection in a monolithic frequency-tuneable laser using coherent time-domain sampling of the laser emission. This approach allows us to observe hopping between lasing modes on picosecond-timescales and the temporal evolution of transient multi-mode emission into steady-state single mode emission. The underlying physics is explained through a full multi-mode, temperature-dependent carrier and photon transport model. Our results show that the fundamental limit on the timescales of frequency-switching between competing modes varies with the underlying Vernier alignment of the laser cavity.

Single-mode, tuneable monolithic semiconductor lasers are important light sources for integrated photonics. Here, Kundu et al. observe the switch-on dynamics and mode competition of a terahertz quantum cascade laser and explain the behaviour with a carrier and photon transport model.

Gas spectroscopy with integrated frequency monitoring through self-mixing in a terahertz quantum-cascade laser

We demonstrate a gas spectroscopy technique, using self-mixing in a 3.4 terahertz quantum-cascade laser (QCL). All previous QCL spectroscopy techniques have required additional terahertz instrumentation (detectors, mixers, or spectrometers) for system pre-calibration or spectral analysis. By contrast, our system self-calibrates the laser frequency (i.e., with no external instrumentation) to a precision of 630 MHz (0.02%) by analyzing QCL voltage perturbations in response to optical feedback within a 0-800 mm round-trip delay line. We demonstrate methanol spectroscopy by introducing a gas cell into the feedback path and show that a limiting absorption coefficient of ∼1×10^-4  cm^-1 is resolvable.

The American Society for Clinical Pathology's 2016-2017 Vacancy Survey of Medical Laboratories in the United States

OBJECTIVES

To determine the extent and distribution of workforce shortages within the nation's medical laboratories.

METHODS

The 2016-2017 Vacancy Survey was conducted through collaboration between the American Society for Clinical Pathology's Institute of Science, Technology, & Policy in Washington, DC, and the Evaluation, Measurement, and Assessment division and Board of Certification in Chicago, Illinois. Data were collected via an internet survey that was distributed to individuals who were able to report on staffing and certifications for their laboratories.

RESULTS

Results of the 2016-2017 Vacancy Survey shows decreased vacancy rates for laboratory positions across all departments surveyed compared with 2014. While overall, the data show that vacancy rates are decreasing, overall retirement rates and certification requirements are higher.

CONCLUSIONS

Focus on the qualifications and certification status of laboratory professionals would be crucial factors in addressing the needs of the laboratory workforce. The field needs to intensify its efforts on recruiting the next generation of laboratory personnel.

Multi-spectral terahertz sensing: proposal for a coupled-cavity quantum cascade laser based optical feedback interferometer

We propose a laser feedback interferometer operating at multiple terahertz (THz) frequency bands by using a pulsed coupled-cavity THz quantum cascade laser (QCL) under optical feedback. A theoretical model that contains multi-mode reduced rate equations and thermal equations is presented, which captures the interplay between electro-optical, thermal, and feedback effects. By using the self-heating effect in both active and passive cavities, self-mixing signal responses at three different THz frequency bands are predicted. A multi-spectral laser feedback interferometry system based on such a coupled-cavity THz QCL will permit ultra-high-speed sensing and spectroscopic applications including material identification.

Quasi-continuous frequency tunable terahertz quantum cascade lasers with coupled cavity and integrated photonic lattice

We demonstrate quasi-continuous tuning of the emission frequency from coupled cavity terahertz frequency quantum cascade lasers. Such coupled cavity lasers comprise a lasing cavity and a tuning cavity which are optically coupled through a narrow air slit and are operated above and below the lasing threshold current, respectively. The emission frequency of these devices is determined by the Vernier resonance of longitudinal modes in the lasing and the tuning cavities, and can be tuned by applying an index perturbation in the tuning cavity. The spectral coverage of the coupled cavity devices have been increased by reducing the repetition frequency of the Vernier resonance and increasing the ratio of the free spectral ranges of the two cavities. A continuous tuning of the coupled cavity modes has been realized through an index perturbation of the lasing cavity itself by using wide electrical heating pulses at the tuning cavity and exploiting thermal conduction through the monolithic substrate. Single mode emission and discrete frequency tuning over a bandwidth of 100 GHz and a quasi-continuous frequency coverage of 7 GHz at 2.25 THz is demonstrated. An improvement in the side mode suppression and a continuous spectral coverage of 3 GHz is achieved without any degradation of output power by integrating a π-phase shifted photonic lattice in the laser cavity.

Origin of terminal voltage variations due to self-mixing in terahertz frequency quantum cascade lasers

We explain the origin of voltage variations due to self-mixing in a terahertz (THz) frequency quantum cascade laser (QCL) using an extended density matrix (DM) approach. Our DM model allows calculation of both the current-voltage (I-V) and optical power characteristics of the QCL under optical feedback by changing the cavity loss, to which the gain of the active region is clamped. The variation of intra-cavity field strength necessary to achieve gain clamping, and the corresponding change in bias required to maintain a constant current density through the heterostructure is then calculated. Strong enhancement of the self-mixing voltage signal due to non-linearity of the (I-V) characteristics is predicted and confirmed experimentally in an exemplar 2.6 THz bound-to-continuum QCL.

Engineered far-fields of metal-metal terahertz quantum cascade lasers with integrated planar horn structures

The far-field emission profile of terahertz quantum cascade lasers (QCLs) in metal-metal waveguides is controlled in directionality and form through planar horn-type shape structures, whilst conserving a broad spectral response. The structures produce a gradual change in the high modal confinement of the waveguides and permit an improved far-field emission profile and resulting in a four-fold increase in the emitted output power. The two-dimensional far-field patterns are measured at 77 K and are agreement in with 3D modal simulations. The influence of parasitic high-order transverse modes is shown to be controlled by engineering the horn structure (ridge and horn widths), allowing only the fundamental mode to be coupled out.

Discrete Vernier tuning in terahertz quantum cascade lasers using coupled cavities

Discrete Vernier frequency tuning of terahertz quantum cascade lasers is demonstrated using a device comprising a two-section coupled-cavity. The two sections are separated by a narrow air gap, which is milled after device packaging using a focused ion beam. One section of the device (the lasing section) is electrically biased above threshold using a short current pulse, while the other section (the tuning section) is biased below threshold with a wider current pulse to achieve controlled localized electrical heating. The resulting thermally-induced shift in the longitudinal cavity modes of the tuning section is engineered to produce either a controllable blue shift or red shift of the emission frequency. This discrete Vernier frequency tuning far exceeds the tuning achievable from standard ridge lasers, and does not lead to any corresponding change in emitted power. Discrete tuning was observed over bandwidths of 50 and 85 GHz in a pair of devices, each using different design schemes. Interchanging the lasing and tuning sections of the same devices yielded red shifts of 20 and 30 GHz, respectively.

Paraganglioma of external auditory canal

In the ear, paragangliomas are commonly found in the tympanic cavity or in juglar bulb. We, here, present a case of paraganglioma originating from the external auditory canal as it has not been reported in the world literature. The clinico-pathologic features of such a case has been described.