How is laser line width measured?

One frequently used method for measuring laser spectral linewidth is the self-heterodyne beat method. In this method, the signal is passed through a fiber Mach-Zender interferometer with a path length imbalance in one arm and an AOM frequency shifter in the other (fig. 1).

What is the bandwidth of a laser?

A light source can have some optical bandwidth (or linewidth), meaning the width of the optical spectrum of the output. The narrow-linewidth lasers, where the bandwidth can be extremely small – sometimes below 1 Hz, which is many orders of magnitude less than the mean optical frequency.

How narrow is a laser?

The laser linewidth in a typical single-transverse-mode He-Ne laser (at a wavelength of 632.8 nm), in the absence of intracavity line narrowing optics, can be on the order of 1 GHz. The laser linewidth from stabilized low-power continuous-wave lasers can be very narrow and reach down to less than 1 kHz.

How is the linewidth of a semiconductor laser increased?

Henry then found that the linewidth of the laser should be increased by the factor (1 + α2), which turned out to be in reasonable agreement with experimental data. It is possible to calculate the α factor of a semiconductor for a given carrier density from a band structure model, although this is not easy.

What is the linewidth of a He-Ne laser?

An alternative approach is the use of spectrometry. The laser linewidth in a typical single- transverse-mode He-Ne laser (at a wavelength of 632.8 nm), in the absence of intracavity line narrowing optics, can be on the order of 1 GHz.

What is the linewidth of a 1064 nm YAG laser?

For comparison, if you temporally stretch the output of a 1064-nm Nd:YAG laser with a 10-kHz linewidth to 440 Hz, the linewidth will be ≈ 16 nHz – a pretty pure tone indeed! the linewidth (FWHM) is proportional to the square of the resonator bandwidth divided by the output power (assuming that there are no parasitic resonator losses).

What are the basics of a semiconductor laser?

Chapter 11 Basics of Semiconductor Lasers Semiconductor Optoelectronics (Farhan Rana, Cornell University) Chapter 11 Basics of Semiconductor Lasers 11.1 Introduction 11.1.1 Introduction to Semiconductor Lasers: In semiconductor optical amplifiers (SOAs), photons multiplied via stimulated emission.