DPSS Amplifiers: Diode-Pumped Solid-State Laser Amplifiers

What is a DPSS amplifier?

A DPSS amplifier or solid-state amplifier is a sub-type of optical amplifiers, utilizing different combinations of doped solid-state media (e.g., Nd:YAG, Yb:YAG, Ti:Sa, etc.) and geometries (rod, disk, slab, etc.) to amplify the input optical signal.

Solid-state amplifiers can be utilized to increase the power or energy from a source laser or signal laser, maintaining any spectral, temporal, or spatial properties. The amplifier’s primary function is to increase the brightness of your source laser beam. Several techniques are available for amplifying continuous-wave (CW) or pulsed laser power, including using a master-oscillator power amplifier (MOPA), a seeded or injection-locked power oscillator, or a regenerative amplifier, for example.

In both a laser and an optical amplifier, energy (the excitation source) is pumped into a gain material until more molecules or atoms are in an excited energy state than the ground state, as shown in the figure below. Once this condition, population inversion, is satisfied, the gain medium is now cable of supporting stimulated emission, which allows photons with energy equal to the energy level gap to be amplified. While a detailed analysis of how stimulated emission works, is beyond the scope of this blog post, a simplified explanation is that the incident photon “knocks” the atom or molecule down to a lower level causing an identical photon to be emitted by the medium following the laws of conservation of energy and momentum.

The difference between lasers and amplifiers comes in when we look at the origin of the incident photon. In a laser, the resonator “catches” a spontaneously emitted photon. It then redirects it back into the gain medium repeatedly until the laser gain threshold is reached, initiating the lasing process. In an optical amplifier, though, there is no resonator. Instead, the photons come from an outside source known as a seed laser, which is then amplified via stimulated emission as it passes through the length of the amplifier. As a result, you can now take a lower power laser with your desired properties (linewidth, pulse width, beam profile, etc.) and increase its power without affecting its overall performance.

There are a wide variety of optical amplifiers available on the market, including semiconductor tapered amplifiers, erbium-doped fiber amplifiers, and diode-pumped solid-state (DPSS) amplifiers, just to name a few. While each has its advantages and disadvantages, DPSS amplifiers are typically viewed as the most versatile because they can be used with an extensive range of seed lasers, ranging from high peak power q-switched lasers to single-frequency continuous-wave lasers sources.

Our DPSS Amplifier Products

RPMC Lasers provides two different amplifier mediums for our DPSS or Solid-State amplifiers to meet a variety of application needs:

neoVan

The neoVAN series is an OEM, solid-state optical amplifier system used to boost the pulse energy or average output powers of laser sources for a variety of applications.  The flexible system design allows a selection of different power and energy levels based on highly reliable, long lifetime gain modules.  The ultra-compact and nearly monolithic modules allow easy integration and cost-effective upgrading of laser application machines, scientific lasers, or low power oscillators.  Whether it be high peak power, short pulse picosecond lasers for micromachining applications or single frequency radiation for gravitational wave detection, the neoVAN amplifier modules will provide a boost to your application. While the fiber-coupled, high gain module allows direct amplification of mode-locked oscillators, gain switched or narrow linewidth diodes, the standard free-space modules scale microchip lasers either into high average power or high energy levels.

neoYb

The neoYb is an OEM type solid-state laser amplifier module to boost the pulse energy or average output power for various applications. It is a stand-alone module containing an amplifier and pump diode and is based on highly reliable and long lifetime newLASE technology. The ultra-compact and nearly monolithic modules allow easy integration and cost-effective upgrading of laser machines, scientific lasers or low power oscillators. It is the ideal power or energy booster for femtosecond laser systems. The neoLASE amplifier modules allow CPA-free amplification for bandwidth-limited pulses in the smallest available footprint. This enables high peak power short pulse pico- or femtosecond lasers for a wide range of micromachining applications without complex compressor arrangements. The high gain pre-amplifier module allows direct amplification of mode-locked oscillators or gain switched diodes. The main amplifier modules are an ideal power or energy booster stage exceeding 50W output power!