Comparative study of thulium fiber laser versus holmium:yttrium-aluminum-garnet laser for ureteric stone management with semi-rigid ureteroscopy: A prospective, single-center study

Objective:To compare the efficacy and safety of thulium fiber laser(TFL)and holmium:yttrium-aluminum-garnet(Ho:YAG)laser for ureteric stone management with semi-rigid ureteroscopy.Methods:In a prospective study from January 2020 to December 2021,we compared 40 patients in each group who underwent semi-rigid ureteroscopic lithotripsy with TFL and that with Ho:YAG laser.Stone volume,stone density,stone fragmentation rates,total lasing time,total operative time,endoscopic vision,retropulsion and stone free rates were analyzed in both groups and compared.Results:Mean stone volume was comparable in the TFL group and the Ho:YAG laser group(282.45[standard deviation,SD 139.79]mm3 vs.279.49[SD 312.52]mm3;p=0.964).Mean stone density was also comparable in the TFL group and the Ho:YAG laser group(1135.30[SD 317.04]Hounsfield unit vs.1131.75[SD 283.03]Hounsfield unit;p=0.959).The mean stone fragmentation rates calculated as stone volume divided by lasing time were 25.85(SD 10.61)mm3/min and 21.37(SD 14.13)mm3/min in the TFL group and the Ho:YAG laser group,respectively(p=0.113).The mean total lasing time(10.15[SD]4.69 min vs.11.43[SD 4.56]min;p=0.222),mean operative time(25.13[SD 9.51]min vs.25.54[SD 10.32]min;p=0.866),and mean total hospital stay(2.62[SD 0.77]days vs.2.61[SD 0.84]days;p=0.893)were comparable in the TFL group and in the Ho:YAG group.The vision was better and retropulsion was less in the TFL group.The stone-free rate at 1 month postoperatively was slightly better in the TFL group(100%vs.90%;p=0.095).

Two-micron （thulium） laser resection of the prostate- tangerine technique： a new method for BPH treatment

Two-micron （thulium） laser resection of the prostate-tangerine technique （TmLRP-TT） is a transurethral procedure that uses a thulium laser fiber to dissect whole prostatic lobes off the surgical capsule, similar to peeling a tangerine. We recently reported the primary results. Here we introduce this procedure in detail. A 70-W, 2-um （thulium） laser was used in continuous-wave mode. We joined the incision by making a transverse cut from the level of the verumontanum to the bladder neck, making the resection sufficiently deep to reach the surgical capsule, and resected the prostate into small pieces, just like peeling a tangerine. As we resected the prostate, the pieces were vaporized, sufficiently small to be evacuated through the reseetoscope sheath, and the use of the mechanical tissue morcellator was not required. The excellent hemostasis of the thulium laser ensured the safety of TmLRP-TT. No patient required blood transfusion. Saline irrigation was used intraoperatively, and no case of transurethral resection syndrome was observed. The bladder outlet obstruction had clearly resolved after catheter removal in all cases. We designed the tangerine technique and proved it to be the most suitable procedure for the use of thulium laser in the treatment of benign prostatic hyperplasia （BPH）. This procedure, which takes less operative time than standard techniques, is safe and combines efficient cutting and rapid organic vaporization, thereby showing the great superiority of the thulium fiber laser in the treatment of BPH. It has been proven to be as safe and efficient as transurethral resection of the prostate （TURP） during the 1-year follow-up.

Thulium laser treatment for bladder cancer

Recent innovations in thulium laser techniques have allowed application in the treatment of bladder cancer.Laser en bloc resection of bladder cancer is a transurethral procedure that may offer an alternative to the conventional transurethral resection procedure.We conducted a review of basic thulium laser physics and laser en bloc resection procedures and summarized the current clinical literature with a focus on complications and outcomes.Literature evidence suggests that thulium laser techniques including smooth incision,tissue vaporization,and en bloc resection represent feasible,safe,and effective procedures in the treatment of bladder cancer.Moreover,these techniques allow improved specimen orientation and accurate determination of invasion depth,facilitating correct diagnosis,restaging,and reevaluation of the need for a second resection.Nonetheless,large-scale multicentre studies with longer follow-up are warranted for a robust assessment.The present review is meant as a quick reference for urologists.

Generation and evolution of multiple operation states in passively mode-locked thulium-doped fiber laser by using a graphene-covered-microfiber

Using graphene-covered-microfiber （GCM） as a saturable absorber, the generation and evolution of multiple operation states are proposed and demonstrated in passively mode-locked thulium-doped fiber laser. The microfiber was fabricated using the flame brushing method to an interaction length of - 1.2 cm with a waist diameter of -10 μm. Graphene layers were grown on copper foils by chemical vapor deposition and transferred onto the polydimethylsiloxane （PDMS） to form a PDMS/graphene film, which allowed light-graphene interaction via evanescent field. With the increase of the pump power from 1.25 W to 2.15 W, five different lasing regimes, including continuous-wave, conventional soliton mode-locking, multi- soliton mode-locking, a period of transition, and noise-like mode-locking, were achieved in a fiber ring cavity. To the best of our knowledge, it is the first report of the generation and evolution of multiple operation states by covering graphene on the microfiber in the 2-μ.m region. The results demonstrate that GCM can be a promising method for fabricating all fiber SA, and the switchable operation states can provide more portability in complex application domain.

A theoretical and experimental investigation of an in-band pumped gain-switched thulium-doped fiber laser

In this paper, the theoretical rate equation model of an in-band pumped gain-switched thulium-doped fiber （TDF） laser is investigated. The analytical formulations of pump energy threshold, peak power extraction efficiency, and pulse extraction efficiency are derived through analyzing the interaction process between the pump pulse and the laser pulse. They are useful for understanding, designing, and optimizing the in-band pumped TDF lasers in a 1.9 μm-2.1 μm wavelength region. The experiment with an all-fiber gain-switched TDF laser pumped by a 1.558-μm pulse amplifier is conducted, and our experimental results show good agreement with theoretical analysis.

Spectroscopic study of thulium doped transparent glass ceramics

A systematic investigation on fluorescence spectroscopy of trivalent thulium doped in oxyfluoride glass ceramics containing LaF3 nanocrystals has been carried out in a spectral range from 400 to 900 nm under the direct excitation of 1D2 level at a low temperature. Specific optical transitions related to the fluorescence emissions are studied based on experimental measurements in frequency and time domain. Fluorescence emissions from the ions in crystal phase are distinguished from what in glass phase and their spectroscopic properties are explored. The dynamical process shows that the temporal decay of fluorescence emission consists of two parts： a rapid decay from the ions in glass phase and a slower decay from the ions in crystal phase.

Magneto-optical effect of TEB30A liquid crystal doped with thulium oxides

The influences of an external magnetic field on the optical properties of the TEB30A nematic liquid crystal doped with thulium oxides （Gd203, Dy203, Nd203, Y203, and Sm203） are studied. It is shown that a magnetic field applied parallelly to the sample cell surface leads to the rotational orientation of mesogenes. All samples except for the sample doped with Sm203 nanoparticles undergo structural deformations. The behavior of the TEB30A/Sm203 differs from those of the TEB30A liquid crystal doped with other four nanoparticles. The presence of Sm203 nanoparticles in the TEB30A liquid crystal does not cause the structural deformation of the liquid crystal matrix. At the same time, the anchoring type of the liquid crystal molecules on the nanoparticle surface is different. The director n is parallel to the magnetic moment/~ in the TEB30A/Sm203, and inclined to the magnetic moment/~ in the TEB30A/Nd203, and perpendicular to the magnetic moment/~ in each of TEB30A/Gd203, TEB30A/Dy203, and TEB30A/Y203. Besides, the dependence of the structural deformation on the critical magnetic field for the TEB30A is obtained.

Thulium fiber laser lithotripsy:Is it living up to the hype?

Objective:The holmium:yttrium-aluminium-garnet laser(Ho:YAG)has been the gold standard for laser lithotripsy over the last three decades.After demonstrating good in vitro efficacy,the thulium fiber laser(TFL)has been recently released in the market and the initial clinical results are encouraging.This article aims to review the main technology differences between the Ho:YAG laser and the TFL,discuss the initial clinical results with the TFL as well as the optimal settings for TFL lithotripsy.Methods:We reviewed the literature focusing on the technological aspects of the Ho:YAG laser and TFL as well as the results of in vitro and in vivo studies comparing both technologies.Results:In vitro studies show a technical superiority of TFL compared to the Ho:YAG laser and encouraging results have been demonstrated in clinical practice.However,as TFL is a new technology,limited studies are currently available,and the optimal settings for lithotripsy are not yet established.Conclusion:TFL has the potential to be an alternative to the Ho:YAG laser,but more reports are still needed to determine the optimal laser for lithotripsy of urinary tract stones when considering all parameters including effectiveness,safety,and costs.

An experimental study of hydrolytic behavior of thulium in basic and near-neutral solutions

Hydrolytic equilibria of Tm (III) in KOH solutions were studied at 25°C. A spectrophotometry with m-cresol purple and 2-naphthol as pH indicators was used at an ionic strength of not more than 0.0005. The results indicate that in freshly prepared solutions at pH ranging between 6 and 10 Tm is present as , , and . The stepwise stability constants of hydroxide complexes calculated at zero ionic strength were obtained as coefficient of linear regression equations from the graph of optical densities of the indicators in Tm solutions at varying pH.

Mode-Locked Thulium Ytterbium Co-Doped Fiber Laser with Graphene Oxide Paper Saturable Absorber

A mode-locked thulium ytterbium co-doped fiber laser （TYDFL） is proposed and demonstrated by using a commercial graphene oxide （GO） paper as saturable absorber （SA）. The GO paper is sandwiched between two fiber ferrules and incorporates a ring laser cavity to generate soliton pulse train operating at 1942.0nm at a threshold multimode pump power as low as 1.8 W. The mode-locked TYDFL has a repetition rate of 22.32 MHz and the calculated pulse width of 1.1 ns. Even though the SA has a low damage threshold, the easy fabrication of GO paper should promote its potentiM application in ultrafast photonics.

Feasibility of en bloc thulium laser enucleation of the prostate in a large case series. Are results enhanced by experience?

Objective:To provide the first large single-operator case series of patients who undergo“en bloc”thulium laser enucleation of the prostate(ThuLEP)and to demonstrate an improvement in enucleation efficacy with experience.Methods:We prospectively evaluated a cohort of patients with symptomatic benign prostatic hyperplasia(BPH)who underwent“en bloc”ThuLEP between May 2015 and November 2017.Association between dependent variables(delivered energy and operating time)and independent variables(adenoma volume and experience)were estimated with regression analysis.The experience was calculated as the time interval between the date of the first operation of the series and the date of the operation being considered.Results:A total of 100 patients were registered for the study.Median operative time was 56.5 min(interquartile range[IQR]:40-85 min).Median enucleation time was 17.4 min(IQR:15-21.5 min).Median enucleation index(enucleation time per adenoma gram)was 0.3 min/g(0.2-0.3 min/g).The overall operative time is not influenced by experience,but we registered a significant trend towards a reduction in the total amount of energy delivered energy normalized per adenoma gram(p=0.0148).Conclusion:We believe that further attention is needed for these new“en bloc”prostatic enucleation techniques,which can facilitate some surgical steps,leading to a widespread use of laser technology for BPH surgical treatment.

Analysis of gain distribution in cladding-pumped thulium-doped fiber laser and optical feedback inhibition problem in fiber-bulk laser system

The steady-state gain distribution in cladding pumped thulium-doped fiber laser（TDFL） is analytically and numerically solved based on the rate equations including loss coefficients and cross relaxation effect. With the gain curve, a problem, which is named optical feedback inhibition（OFI） and always occurs in tandem TDFL-Ho：YAG laser system, is analyzed quantitatively. The actual characteristics of output spectra and power basically prove the conclusion of theoretical analysis. Then a simple mirror-deflected L-shaped cavity is employed to restrain the external feedback and simplify the structure of fiber-bulk Ho：YAG laser. Finally, 25 W of 2097-nm laser power and 51.2% of optical-to-optical conversion efficiency are obtained, and the beam quality factor is less than 1.43 obtained by knife-edge method.

Observation of Violet-Light Emission Band for Thulium-Doped Tantalum-Oxide Films Produced by Co-Sputtering

We prepared thulium-doped tantalum (V) oxide (Ta2O5:Tm) thin films using co-sputtering of two Tm2O3 pellets and a Ta2O5 disc, and we observed photoluminescence (PL) peaks not only around a wavelength of 800 nm due to the 3H4→3H6 transition of Tm3+ but also around a wavelength of 400 nm (violet) from the films after annealing for the first time. Comparatively narrow PL peaks around the wavelength of 400 nm were observed from the films annealed at 800°C and 900°C for 20 min. The peak intensity from the film annealed at 900°C was approximately four-times stronger than that from the film annealed at 800°C. The origin of the 400-nm peaks seems to be the same as our non-doped Ta2O5 thin films deposited using radio-frequency sputtering because we observe PL peaks around 400 - 430 nm from the Ta2O5 films. Such a Ta2O5:Tm co-sputtered thin film seems to be used as a multi-functional coating film having both anti-reflection and down-conversion effects for realizing a high-efficiency silicon solar cell.

Photoluminescence Properties of Thulium and Cerium Co-Doped Tantalum-Oxide Films Prepared by Radio-Frequency Co-Sputtering

We prepared thulium and cerium co-doped tantalum-oxide (Ta2O5 :Tm, Ce) thin films by radiofrequency co-sputtering of Tm2O3 and CeO2 pellets on a Ta2O5 disc for the first time, and photoluminescence (PL) properties of the films annealed at 700°C, 800°C, 900°C, or 1000°C for 20 min were evaluated. PL peaks around a wavelength of 800 nm due to Tm3+?were observed for films annealed at 900°C or 1000°C. The peak intensities of films prepared using one Tm2O3 pellet and one CeO2 pellet were much stronger than those of films prepared using one Tm2O3 pellet and two CeO2 pellets or films prepared using two Tm2O3 pellets and one CeO2 pellet. To obtain the strongest PL intensity from the film, the proper Tm concentration was estimated to be around 1.0 mol%, and the proper Ce concentration was estimated to be around 1.3 mol%. Such Ta2O5:Tm, Ce co-sputtered thin films can be used as high-refractive-index materials of autocloned photonic crystals that can be applied to novel light-emitting devices, and they will also be used as anti-reflection and downconversion layers for realizing high-efficiency silicon solar cells.

Thulium Doped Fiber Amplifier (TDFA) for S-band WDM Systems

A comprehensive numerical model based on solving rate equations of a thulium-doped silica-based fiber amplifier is evaluated. The pump power and thulium-doped fiber (TDF) length for single-pass Thulium-Doped Fiber Amplifiers (TDFA) are theoretically optimized to achieve the optimum Gain and Noise Figure (NF) at the center of S-band region. The 1064 nm pump is used to provide both ground-state and excited state absorptions for amplification in the S-band region. The theoretical result is in agreement with the published experimental result.

Two-micrometer thulium laser resection of the prostate-tangerine technique in benign prostatic hyperplasia patients with previously negative transrectal prostate biopsy

The 2-1μm thulium laser resection of the prostate-tangerine technique （TmLRP-TT） has been introduced as a minimally invasive treatment for benign prostatic hyperplasia （BPH）. This study was undertaken to assess the clinical efficacy and safety of TmLRP-TT for the treatment of BPH patients with previously negative transrectal prostate biopsy. A prospective analysis of 51 patients with previously negative transrectal prostate biopsy who underwent surgical treatment using TmLRP-TT was performed from December 2011 to December 2013. Preoperative status, surgical details, and perioperative complications were recorded. The follow-up outcome was evaluated with subjective and objective tests at I and 6 months. TmLRP-TT was successfully completed in all patients. Mean prostate volume, operative duration, and catheterization time were 93.3 ± 37.9 ml, 69.5 ± 39.5 min, and 6.5 ± 1.3 days, respectively. The mean International Prostate Symptom Score, quality of life score, maximum urinary flow rate, and post-void residual urine volume changed notably at 6-month follow-up （22.5 ± 6.9 vs 6.1 ± 3.2, 4.8 ± 1.3 vs 1.1 ± 0.9, 7.3 ± 4.5 vs 18.9 ± 7.1 ml s^-1, and 148.7 ± 168.7 vs 28.4 ± 17.9 ml）. Two （3.9%） patients required blood transfusion perioperatively, while 3 （5.9%） patients experienced transient hematuria postoperatively, and 2 （3.9%） patients received 3 days recatheterization due to clot retention. TmLRP-TT is a safe and effective minimally invasive technique for patients with previously negative transrectal prostate biopsy during the 6-month follow-up. This promising technology may be a feasible surgical method for previously negative transrectal prostate biopsy in the future.

铥原子4f^(13)(^(2)F_(5/2)^(0))6s6p(^(1)P_(1)^(0))(5/2,1)_(7/2)和4f^(13)(^(2)F_(5/2)^(0))6s6p(^(1)P_(1)^(0))(5/2,1)_(5/2)激发态近阈限光电离截面测量

本文利用了激光烧蚀技术、激光泵浦-探测技术、共振增强多光子电离技术(REMPI)和飞行时间质谱技术(TOF-MS)相结合的实验方法研究了镧系金属铥原子激发态近阈限光电离截面.实验研究了Tm原子在291.00~293.50 nm波长范围内的REMPI光谱,在电离富余能0.2~1.0 eV内,测量了Tm原子4f^(13)(^(2)F_(5/2)^(0))6s6p(^(1)P_(1)^(0))(5/2,1)_(7/2)和4f^(13)(^(2)F_(5/2)^(0))6s6p(^(1)P_(1)^(0))(5/2,1)_(5/2)激发态的光电离截面,测量值在(3.3±0.2)Mb~(13.9±1.3)Mb范围内.

Sexual outcome of patients undergoing thulium laser enucleation of the prostate for benign prostatic hyperplasia

Treatment of patients with lower urinary tract symptoms （LUTS） secondary to benign prostatic hyperplasia （BPH） may affect the quality of sexual function and ejaculation. The effect of new surgical procedures, which are currently available to treat BPH, on erection and ejaculation, has been poorly studied. This study aimed to assess the effect of thulium laser enucleation of the prostate （ThuLEP） on sexual function and retrograde ejaculation in patients with LUTS secondary to BPH. We performed a prospective study in 110 consecutive patients who had undergone ThuLEP to analyze changes in sexual function and urinary symptoms. To evaluate changes in erection and ejaculation, and the effect of urinary symptoms on the quality of life （QoL）, five validated questionnaires were used： the ICIQ-MLUTSsex, MSHQ-EjD, International Index of Erectile Function 5, International Prognostic Scoring System （IPSS） questionnaire, and QoL index of the intraclass correlation coefficients. Patients also underwent IPSS and flowmetry to assess the outcome of flow. Patients were evaluated before surgery and 3-6 months after ThuLEP, whereas those with previous abdominal surgery were excluded. The patients＇ mean age was 67.83 years. Postoperative urinary symptoms improved after surgery. No significant differences in erectile function before and after surgery were observed. As compared with other techniques described in the literature, the percentage of patients with conserved ejaculation increased by 52.7% after ThuLEP. ThuLEP positively affects urinary symptoms and their effect on the QoL of patients as assessed by questionnaire scores. While endoscopic management of BPH （e.g. transurethral resection of the prostate） causes retrograde ejaculation in most patients, those who undergo ThuLEP have conserved ejaculation and erectile function.

Efficacy and Safety of 120-W Thulium：Yttrium-Aluminum-Garnet Vapoenucleation of Prostates Compared with Holmium Laser Enucleation of Prostates for Benign Prostatic Hyperplasia

Background： This study compared the efficacy and safety between 120-W thulium：yttrium-aluminum-garnet （Tm：YAG） vapoenucleation of prostates （ThuVEP） and holmium laser enucleation of prostates （HoLEP） for patients with lower urinary tract symptoms （LUTS） due to benign prostatic hyperplasia （BPH）. Methods： A retrospective analysis of 88 consecutive patients with symptomatic BPH was carried out, who underwent either 120-W ThuVEP or HoLEP nonrandomly. Patient demographics and peri-operative and 12-month follow-up data were analyzed with the International Prostate Symptom Score （IPSS）, quality of life （QoL） score, maximum flow rate （Qmax）, postvoid residual urine volume （PVR）＋ and rates of peri-operative and late complications. Results： The patients in each group showed no significant difference in preoperative parameters. Compared with the HoLEP group, patients in the 120-W ThuVEP group required significantly shorter time for laser enucleation （58.3 ± 12.8 min vs. 70.5 ± 22.3 min, P = 0.003）, and resulted in a significant superiority in laser efficiency （resected prostate weight/laser enucleation time） for 120-W Tm：YAG laser compared to holmium：YAG laser （0.69 ± 0.18 vs. 0.61 ± 0.19, P = 0.048）. During 1, 6, and 12 months of follow-ups, the procedures did not demonstrate a significant difference in IPSS, QoL score, Qmax, or PVR （P 〉 0.05）. Mean peri-operative decrease of hemoglobin in the HoLEP group was similar to the ThuVEP group （ 17.1 ± 12.0 g/L vs. 15.2± 10.1 g/L, P = 0.415）. Early and late incidences of complications were low and did not differ significantly between the two groups of 120-W ThuVEP and HoLEP patients （P 〉 0.05）. Conclusions： 120-W ThuVEP and HoLEP are potent, safe and efficient modalities of minimally invasive surgeries for patients with LUTS due to BPH. Compared with HoLEP, 120-W TbuVEP offers advantages of reduction of laser enucleation time and improvement of laser efficiency.

A theoretical model of thulium-doped silica fiber's ASE in the 1900 nm waveband

A theoretical model in the 1900 nm waveband for amplified spontaneous emission (ASE) of thulium-doped silica fiber is presented. The ASE spectral power as functions of the fiber length and the pump power is investigated by solving the rate and propagation equations. By calculation, when the concentration of thulium in fiber is 2.25×1025 m-3, the fiber core diameter is 2.6 μm, and the pump power is 200 mW at 808 nm, the optimal fiber length is 8.1 m, and the output power of ASE can reach 60 mW in the range of 1800-1950 nm with this fiber length. The optical-to-optical conversion is 30.3%. The optimal pump power also can be obtained by this model.