An front facet anti-reflection coated solitary laser diode is operated in the external cavity diode laser (ECDL). For wavelength stabilization and narrow spectral width, the diffraction grating is used in a Littrow configuration. At an injection current of 280 mA, a output power of 35mW with a slope efficiency of 0.22 W/A and the bandwidth of 80 pm at a wavelength of 457 nm. In this paper, the tunable external cavity diode laser module is designed with an overall size of 18 mm x 24 mm x 14 mm. ECDL showed excellent wavelength locking behavior without a non-shift of the peak wavelength.
A red-emitting external cavity diode laser (ECDL) module was designed to increase the slope efficiency and reduce the bandwidth by tilting the solitary laser diode (LD) 90 deg. This tilt resulted in parallel polarization, which yielded high-slope efficiency and also produced a favorable geometry that minimized the area of the back-focused beam, thereby facilitating selection of a specific wavelength. A ray-tracing simulator was used to optimize optical parameters such as the back focal length of the collimating lens, the cavity length, and the grating’s groove density. Based on the optimized structure, an ECDL module package was designed for thermal control by using autodisk computer-aided design tool. The resulting module obtained high-slope efficiency and narrow-bandwidth emission of red light, making it suitable for potential application as a light source for a commercial three-dimensional holographic system. The module achieved the narrow bandwidth of 80 pm and the slope efficiency of 0.81 W/A, which compared favorably with the output power of 0.8 to 0.9 W/A of commercial solitary LDs.
An front facet-low reflection coated broad-area laser(BAL) diode with an emitter size of 50 μm x 1 μm and a chip length
of 2000 μm is operated in the external cavity diode laser(ECDL). For wavelength stabilization and narrow spectral width,
the diffraction grating is used in a Littrow configuration. At an injection current of 1.5 A, a output power of 0.65 W with
a slop efficiency of 0.85 A/W, which is comparable to those of a solitary BAL diode, could be achieved with a spectral
width of 120pm which is about 77 % narrower as compared to a solitary BAL diode. The peak wavelength stability
below 10 pm was obtained in the wide range of output power up to 0.65 W.
External cavity diode laser with broad-area laser diode is operated up to the output power of 160 mW at the injection current of 850 mA and the bandwidth of 80 pm at a wavelength of 648 nm in external cavity. High slope efficiency of output power and narrow bandwidth using broad-area laser (BAL) diode, the width of active layer in the slow axis is too broad to select a specific wavelength. In this paper, more efficient wavelength selection method is investigated by confirming the tendency of grating grooves and designing to set up the wavelength dispersion direction along the fast axis of a solitary laser diode (LD) geometrically. Thus, the tunable external cavity diode laser module by using BAL diode is designed with an overall size of 49 mm x 52 mm x 48.5 mm. From injection current in the range of 650-900 mA, ECDL showed excellent wavelength locking behavior without a non-shift of the peak wavelength. Here, the tuning range is 4 nm with maintaining the narrow bandwidth of 80 pm and up to the output power of 100 mW. A side-mode-suppression of 36.5dB is also achieved at the output power of 160 mW and the injection current of 850 mA.