Local Effects of a 1940 nm Thulium-Doped Fiber Laser and a 1470 nm Diode Laser on the Pulmonary Parenchyma: An Experimental Study in a Pig Model

Abstract

The lungs are a common site of metastases from malignant tumors. Their removal with a minimal but safe tissue margin is essential for the long-term survival of patients. The aim of this study was to evaluate the usefulness of a 1940 nm thulium-doped fiber laser (TDFL) and a 1470 nm diode laser (DL) in a pig model of lung surgery that involved the incision and excision of lung tissue. Histopathological analysis was performed on days 0 and 7 after surgery. Neither TDFL nor DL caused significant perioperative or postoperative bleeding. Histological analysis revealed the presence of carbonized necrotic tissue, mixed fibrin–cellular exudate in the superficial zone of thermal damage and bands of deeper thermal changes. The mean total width of thermal damage on day 0 was 499.46 ± 61.44 and 937.39 ± 109.65 µm for TDFL and DL, respectively. On day 7, cell activation and repair processes were visible. The total width of thermal damage was 2615.74 ± 487.17 µm for TDFL vs. 6500.34 ±1118.02 µm for DL. The superficial zone of thermal damage was narrower for TDFL on both days 0 and 7. The results confirm the effectiveness of both types of laser in cutting and providing hemostasis in the lungs. TDFL caused less thermal damage to the lung parenchyma than DL.

Wavelength-Tunable Single-Longitudinal-Mode Narrow-Linewidth Thulium/Holmium Co-Doped Fiber Laser with Phase-Shifted Fiber Bragg Grating and Dual-Coupler-Ring Filter

“…σ + = 2π∆n/λ (5) where φ denotes the phase chirp, β is the transmission constant, λ B is the center wavelength, Λ is the nominal period, and n e f f = 1.455 is the effective refractive index of the single-mode fiber (SMF). The refractive index modulation of the UFBG is uniformly distributed along the z-axis; thus, dφ/dt = 0.…”

“…The atmospheric transmissivity of lasers near 2040 nm reaches as high as 80% [2]. Eye-safe fiber lasers operating near 2 µm, with strong absorption in animal/human tissues and minimal damage to the retina, are extensively used in medical fields [3][4][5], generating significant research interest. The single-longitudinal-mode (SLM) thulium/holmium co-doped fiber laser (THDFL), which is characterized by low noise, narrow linewidth, high coherence, electromagnetic immunity, and an all-optical fiber structure, shows tremendous potential in various fields including high-resolution spectroscopy, coherent optical communication, LiDAR, and materials processing [6][7][8][9][10].…”

The Dynamics of Multi-Peak Pulsed Generation in a Q-Switched Thulium-Doped Fiber Laser

“…The first thulium-doped (Tm 3+ ) silica-based fiber laser with pumping at λ p = 810 nm and generating in the spectral range of λ s = 1780-2060 nm was experimentally demonstrated in 1990 [3], and since then, these systems have been continuously improved [4][5][6]. These lasers and amplifiers are used in laser surgery [7][8][9], for pumping holmium active elements [10][11][12], as a part of measuring systems [13] and laser LIDARs [14], in scientific research and in other applications [15,16]. Thulium-doped fibers with another glass matrix or structure [17] can be used to operate in the spectral range over the 2000 nm thereby expanding the application area of these laser systems [18][19][20].…”