Coherent tuning of semiconductor laser wavelength

2006 ◽  
Vol 45 (1) ◽  
pp. 014202
Author(s):  
Sahnggi Park
2022 ◽  
Vol 20 (4) ◽  
pp. 56-62
Author(s):  
M. A. Ryabova ◽  
M. Yu. Ulupov ◽  
N. A. Shumilova ◽  
G. V. Portnov ◽  
E. K. Tikhomirova ◽  
...  

Aim of the study was to compare the cutting and coagulation properties of 1.56 and 1.94 μm fiber lasers with those of a 0.98 μm semiconductor laser.Materials and methods. A comparative study of the biological effects of 1.56 and 1.94 µm lasers and a 0.98 µm semiconductor laser used in a constant, continuous mode was carried out. The cutting properties of the lasers were evaluated on the chicken muscle tissue samples by the width and depth of the ablation zone formed via a linear laser incision at a speed of 2 mm/s, while the coagulation properties were assessed by the width of the lateral coagulation zone. The zones were measured using a surgical microscope and a calibration slide. For statistical analysis, power values of 3, 5, 7, 9, and 11 W were chosen for each laser wavelength.Results. Analysis of the findings confirmed that laser wavelength had a statistically significant effect on the linear dependence between incision parameters and laser power. It was found that the 1.56 μm fiber laser (water absorption) had a greater coagulation ability but a comparable cutting ability compared with the 0.98 μm laser (hemoglobin absorption). When used in the power mode of 7W or higher, the 1.94 µm laser provided superior cutting performance compared with the 0.98 µm semiconductor laser at the same exposure power. Elevating the power in any of the lasers primarily increased the width of the ablation zone, and to a lesser extent – the crater depth and the width of the lateral coagulation zone. Therefore, in comparison with the 0.98 μm semiconductor laser, higher radiation power in the 1.56 and 1.94 μm lasers mainly influences their cutting properties, expanding the width and depth of the ablation zone, and has a smaller effect on their coagulation ability.Conclusion. The findings of the study showed that the 1.56 and 1.94 μm fiber lasers have better coagulation properties in comparison with the 0.98 μm semiconductor laser. was statistically proven that all incision characteristics (width of the lateral coagulation zone, depth and width of the ablation zone) for the 1.56, 1.94, and 0.98 μm lasers depend on the power of laser radiation. The 1.94 µm laser is superior to the 0.98 µm laser in its cutting properties. 


2021 ◽  
pp. 116-122
Author(s):  
V. M. Svistushkin ◽  
E. S. Shchennikova ◽  
E. V. Sinkov

Introduction. Chronic rhinitis occurs more often in patients; it’s symptoms deteriorate their quality of life, affect sleeping, daily activity, and sometimes cause complications. The treatment depends on the clinical symptoms. In case of inefficiency of conservative therapy, surgery is indicated. Choosing an exact surgical instrument is still controversial.Objective. The aim of our study is to compare using semiconductor laser (wavelength 1.56 mkm) and radiofrequency (4 MHz) in patients with chronic rhinitis.Materials and methods. 60 patients with chronic drug-induced rhinitis aged 19–80 years were recruited and divided into two equal groups. All patients underwent surgical procedures: semiconductor laser (IRE-Polus) and radiofrequency (Ellman Surgitron) inferior nasal turbinate reduction. To assess and compare the healing process in two groups we used endoscopy and active anterior rhinomanometry. All patients filled out the SNOT-20 questionnaire. For the mucociliary clearance evaluation saccharin test was used. We observed patients during 12 months.Conclusion. Both, laser and radiofrequency, techniques are effective in patients with chronic rhinitis. In laser group shorter healing period was observed, what leads to rehabilitation shortening and life quality improvement. 


1984 ◽  
Vol 5 (2) ◽  
Author(s):  
O. Strobel

SummaryA new detection method has been realized for laser wavelength and power control. A single detector scheme gives simultaneous response of occuring changes in the two laser output parameters of interest. Experimental results showing a wavelength and power stabilization of 10


1985 ◽  
Vol 24 (24) ◽  
pp. 4307 ◽  
Author(s):  
Gen-ichi Hatakoshi ◽  
Kenya Goto

2006 ◽  
Author(s):  
Kuo-Tong Ma ◽  
Chin-Kuei Li ◽  
I. M. Vincent Chiu ◽  
Mason Yen ◽  
Wai William Wang ◽  
...  

2018 ◽  
Vol 42 (1) ◽  
pp. 54-59 ◽  
Author(s):  
D. A. Usanov ◽  
A. V. Skripal ◽  
E. I. Astakhov ◽  
I. S. Kostuchenko ◽  
S. Yu. Dobdin

The capabilities of the method of current-modulated laser wavelength are shown to be extended by using harmonic modulation. Advantages of the sawtooth modulation method associated with using the frequency measurements of the interference signal as an information parameter have been researched. Advantages of the harmonic-type modulation based on the use of measurement results for spectral component amplitudes of the interference signal for distance determination have also been investigated. A comparative analysis of methods for absolute distance measurements at the existing capabilities of semiconductor laser wavelength modulation has demonstrated the benefits of the harmonic modulation of laser diode current for distances under 30 cm, showing the sawtooth current modulation to work better for distances greater than 50 cm.


Author(s):  
Daniel L. Callahan ◽  
H. M. Phillips ◽  
R. Sauerbrey

Excimer laser irradiation has been used to interferometrically ablate submicron line patterns on to Kapton polyimide. Such patterned material may exhibit highly anisotropic conduction as was predicted from previous studies showing enhanced conductivity from uniformly ablated material. We are currently exploiting this phenomenon to create integrated devices using conventional polymers as both dielectrics and conductors. Extensive scanning electron microscopy (SEM) and limited transmission electron microscopy (TEM) have been conducted in order to characterize the morphology of such patterned nanostructures as a function of processing conditions.The ablation technique employed produces an interference pattern on the polymer surface of period equal to half that of a diffraction grating period, independent of the laser wavelength. In these experiments, a 328 nm grating has been used to produce line patterns of 164 nm line-spacings as shown in Figures 1 and 2. A 200 Å Au coating has been used to both prevent charging and, perhaps more importantly, enhance contrast.


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