Cutting Edge Optronics (CEO) has further advanced its high-performance diode-pumped solid-state (DPSS) laser product offerings with the development and testing of two Er:YAG laser modules. Each system incorporates an erbium-doped yttrium aluminum garnet (Er:YAG) crystal as the gain medium, optically pumped by CEO’s in-house-manufactured 97X nm laser diodes. This effort continues CEO’s long heritage of precision-engineered DPSS solutions for industrial, medical, and scientific markets, showcasing optimized efficiency, stability, and scalability in mid-infrared laser systems.

Why the 2.94 μm Er:YAG Wavelength Matters

The 2.94 μm emission wavelength is one of the most significant characteristics of Er:YAG lasers. This wavelength corresponds precisely with a strong absorption peak of water — the dominant component in soft biological tissue — giving it a unique advantage in medical and dental applications. When operating at 2.94 μm, tissue ablation occurs with exceptional precision and minimal thermal damage, as the laser energy is rapidly absorbed and dissipated without significant penetration beyond the target region.

The Er:YAG’s energy absorption profile also aligns well with the optical properties of hard tissues like bone, dentin, and enamel. For this reason, the laser has become a preferred tool for procedures such as dental drilling, cavity preparation, dermatological resurfacing, and orthopedic microsurgery. Beyond medicine, this wavelength is also valuable in scientific instrumentation and mid-infrared laser pumping, where efficient wavelength conversion and high beam quality are essential.

Er:YAG Laser Module Designs and Specifications

CEO evaluated two Er:YAG DPSS laser configurations designed to cover a wide performance range. The first, designated the RBAT model, employs a compact 2 mm diameter rod pumped by 45 diode bars, optimized for low-energy but high-repetition-rate operation. This configuration targets applications requiring less than 1 J per pulse, such as dermatological treatments or soft-tissue medical systems where precision and speed are critical.

The second, larger configuration, the REA model, uses a 5 mm diameter Er:YAG rod pumped by 160 diode bars. This design is intended for high-energy output exceeding 1 J per pulse, suitable for materials research, bone ablation, or as a pump source in multi-stage laser systems. These two experimental setups were selected to span a representative range of medical and industrial needs, demonstrating the scalability of the Er:YAG platform. Future configurations can be readily customized by adjusting diode array power, rod length, and cooling geometry to meet specific energy and repetition-rate requirements.

Output performance across both module types is presented in the accompanying graphs, showing the relationship between output energy and pump energy at multiple pulse durations (150-1500 μs) and repetition rates (10–100 Hz). These test results confirm near-linear energy scaling in both designs up to saturation limits, validating the efficiency of CEO’s diode-pumped architecture.

Performance Testing and Energy Output Results

During performance testing, the 2 mm RBAT module demonstrated particularly promising results. Operating at a 100 Hz repetition rate, it achieved pulse energies exceeding 100 mJ, establishing it as an effective platform for applications that demand both high pulse repetition and accurate energy delivery — a crucial requirement in photocoagulation, skin resurfacing, and minimally invasive surgical systems.

Conversely, the 5 mm REA system produced multi-Joule output levels at lower repetition rates, confirming its potential for laser sources where peak power is prioritized over speed. These findings highlight the adaptability of CEO’s DPSS module design: from compact, fast-pulsing Er:YAG systems to robust, high-energy configurations, the architecture remains consistent, modular, and thermally efficient.

An important observation is the consistent slope efficiency across configurations, a direct result of CEO’s optimized diode coupling and gain medium design. The company’s proprietary mounting techniques ensure precise thermal management and optical alignment, allowing stable performance across multiple operating regimes. The results affirm that CEO’s DPSS integration methodology yields reliable energy scaling, high optical-to-optical efficiency, and consistent beam output under varying operational conditions.

Long-Term Reliability and Proven DPSS Design

Reliability remains a cornerstone of any DPSS technology intended for clinical and research environments. Both the RBAT and REA Er:YAG modules are based on CEO’s long-standing, field-proven module designs used worldwide for oscillator and amplifier systems. These modules routinely achieve operational lifetimes exceeding 10 billion pulses, a metric that surpasses the expected service life of most medical laser systems.

The robust mechanical and thermal design minimizes degradation of optical components, while the diode arrays — built in-house — undergo extensive qualification to ensure consistency across production batches. This vertically integrated approach allows for strict quality control at every stage, from diode fabrication to final system assembly. In turn, customers benefit from predictable performance, simplified maintenance, and long-term cost efficiency.

Conclusion

CEO’s new Er:YAG modules offer a ready-made pump source for medical laser applications. Combining efficient diode pumping, precision-engineered rods, and rigorous lifetime testing, these modules provide a foundation for future medical and industrial technologies that rely on precise energy delivery at the 2.94 μm wavelength.

The RBAT and REA series diode-pumped solid-state (DPSS) gain modules from Cutting Edge Optronics serve as central building blocks for high energy, high repetition rate burst-mode laser systems. Burst-mode laser systems achieve high pulse energy in combination with high repetition rate operation by grouping a series of closely spaced pulses into short bursts, thereby reducing the overall average system power. Diode pumping enables burst durations on the order of 100 ms, in contrast to flashlamp-pumped systems, which are limited to about 10 ms bursts. Repetition rates within the burst can be tunable from a single pulse to 1MHz with flexible pulse durations. A sequence of RBAT and REA modules with rod sizes ranging from 2 mm to 32 mm, along with Cutting Edge Optronics’ eDrive laser diode drive electronics, are key components in producing bursts with better than 1% burst-to-burst stability and better than 2% pulse-to-pulse stability within the burst. A long pulse burst-mode laser system provides an alternative to continuously pulsed and CW lasers in applications such as flow diagnostics and other scientific research. 

RBAT Modules – Compact, Flexible Gain Modules

• The RBAT series offers rod diameters from 2 mm to 4.5 mm, using standard gain media such as Nd:YAG or Nd:YLF.
• These modules can operate under continuous wave (CW) or quasi-continuous wave (QCW) pumping.
• In practical systems, RBAT modules support CW output powers up to approximately 150 W and long-pulse energies around 500 mJ.
• Because of their small size and flexibility, RBAT modules are suitable as the master oscillator or initial amplifier stage in diode-pumped MOPA (master-oscillator power amplification) systems, especially those intended for pulsed, burst-mode or Q-switched operation. 

REA Modules – High Energy, High-Capacity Amplifiers

• The REA series supports larger rod diameters (from 4 mm up to 32 mm), allowing much higher stored energy, which is a critical factor for achieving high output energies.
• Under CW operation, REA modules can deliver output powers up to approximately 650 W.
• For pulsed or burst-mode operation, they can provide high pulse energies – making them well-suited for amplifying seed pulses from oscillators to the energy levels required for demanding applications in both single-pass or multi-pass configurations.
• REA modules can be configured as QCW diode-pumped amplifiers in nanosecond MOPA laser systems or used in unstable resonator designs for high peak energy and high average power applications. 

Why Cutting Edges Optronics’ RBAT + REA Architecture Works Well for Burst-Mode / QCW Lasers

• Operating amplifiers in quasi-CW (QCW) or burst-pumped regimes allows the modules to handle high pump powers intermittently, avoiding the thermal loading and gain medium stress that continuous high-power pumping can cause.
• The modularity – smaller RBAT stages for seeding/oscillation, larger REA stages for amplification, and eDrive laser diode drive electronics for tailored pulse duration – provides flexibility to tailor each laser’s output parameters (pulse energy, burst duration, repetition rate) to specific application requirements.

To explore available RBAT and REA configurations and related drive electronics, visit our laser gain modules catalog.

Approved for Public Release: NG25-2258. © 2026 Cutting Edge Optronics, Inc.

The aesthetic laser market is continually advancing, and at the forefront of this evolution is laser hair removal. The efficacy, safety, and reliability of a hair removal system are paramount. While patients see a sophisticated light delivery device, the heart of the machine, and the component that dictates its performance, is the laser diode stack.

Selecting the right laser diode for hair removal applications is critical for balancing treatment effectiveness, device reliability, and patient comfort and safety. Cutting Edge Optronics (CEO), as a vertically integrated medical laser components manufacturer, delivers advanced solutions tailored to each requirement.

Choosing the right laser diode is not just a technical decision; it’s a business decision that impacts client satisfaction, treatment outcomes, and the bottom line. At Cutting Edge Optronics, we specialize in the high-power laser diodes that drive these systems. 

Wavelength: The Foundation of Effective Treatment

Laser hair removal devices are based on selective photothermolysis—the use of a particular wavelength of light to target and destroy a specific chromophore. In this case, the target is melanin in the hair follicle. The wavelength of the laser determines how effectively and safely this is achieved across different skin and hair types. Three wavelengths dominate the industry: 755 nm (Alexandrite), 800-810 nm (Diode) and 1064 nm (Nd:YAG, Diode). The 755 nm wavelength exhibits very high melanin absorption, and is best for treating fine, light-colored hair on individuals with fair skin types. 1064 nm is the safest option for darker skin tones because it has the lowest melanin absorption and the deepest penetration, allowing it to bypass the surface melanin and target the hair follicle with less risk to the skin. The 800-810 nm wavelength span offers balance between the two, and is best for a range of skin tones, making it a versatile and popular choice.

Many modern systems now incorporate multiple wavelengths to offer comprehensive treatment options. Cutting Edge Optronics now offers diode laser wavelengths in both the 800-810 nm span and at 1064 nm, which can be combined for a more versatile device. 

Power, Fluence, and Pulse Duration: The Efficacy Triangle

While wavelength determines which hair and skin types can be treated, the interplay of power, fluence, and pulse duration determines how well the treatment works. The output power of the laser diode stack dictates the range of possible treatment parameters. A higher-power stack enables the use of larger spot sizes at effective energy levels, which translates to faster and more efficient treatment sessions. Fluence is the actual energy density delivered to the treatment area. Achieving the optimal fluence is critical for thermally destroying the hair follicle without damaging surrounding tissue. The pulse duration must be long enough to heat the follicle to a destructive temperature but shorter than the skin’s Thermal Relaxation Time (TRT) to prevent burns.

CEO’s superior laser diode stacks provide consistent, stable power output, ensuring that the fluence and pulse duration selected on the screen are the same as what’s being delivered to the skin, shot after shot.

Cooling and Construction: The Keys to Longevity and ROI

A high-power laser diode generates a significant amount of heat. Managing this thermal load is arguably the most critical factor in the diode’s lifespan and reliability. Inadequate cooling leads to performance degradation, wavelength shifting, and premature failure.

This is where the physical construction of the diode stack is vital. At Cutting Edge Optronics, we utilize advanced cooling architectures and proprietary assembly techniques to ensure maximum thermal efficiency. A robustly designed and well-cooled diode stack translates directly to a longer lifespan, consistent performance and uptime.

Approved for Public Release: NG25-2258. © 2026 Cutting Edge Optronics, Inc.

Cutting Edge Optronics has demonstrated a 7J, 527nm, 10Hz laser with a 4ns pulse
width and square temporal profile, ideally suited to Optical Parametric Chirped Pulse
Amplification (OPCPA) pumping. DPSS laser technology provides tremendous
advantages over lamp-pumped lasers in meeting the stringent requirements of OPCPA
pump lasers. In particular, the spatial and temporal profiles, the short-term and long-
term pulse energy stability, and the low wavefront distortion of the DPSS laser are an
excellent fit.

By utilizing high quality Nd:YLF crystals and MRF technology, the TWD was minimized
to obtain superior beam quality. The output is nearly diffraction limited with a diameter of
22mm and full angle divergence of ~0.1 mrad at 1053nm. Due to the unique properties
of Nd:YLF, the laser has weak thermal lensing and thermal distortion. This allows
flexibility in its operational frequency. A repetition rate of 10Hz was achieved with a
timing jitter of less than 25ps rms. The beam uniformity over an aperture capturing 90%
of the energy was 7.2% rms. The second harmonic output was generated by a
25x25x15 mm type-I LBO crystal with a conversion efficiency of 78% from a 9.1J,
1053nm output. Output pulse energy stability was 0.45% rms over 10 hours.

Overall, the laser performance results demonstrated that an all diode-pumped Nd:YLF
laser is an excellent solution for the requirements of OPCPA pumping. See additional
information below.

Approved for Public Release: NG25-0505. © 2025 Cutting Edge Optronics, Inc.

Cutting Edge Optronics (CEO) recently built and tested one of their industry standard REA diode-
pumped solid-state (DPSS) laser modules with an Er:YAG rod as the gain medium and pumped with in-house-manufactured 97Xnm laser diodes. The Er:YAG rod was provided by Northrop Grumman
SYNOPTICS. The module’s laser emission wavelength is 2.94μm, which is highly absorbed by water
and hydroxyapatite. A laser at this wavelength has a variety of applications in the medical and
scientific laser communities such as dental surgery, wart removal, the cutting of bone and soft
tissue, as well as for pumping mid-wave IR lasers.

Test results from an REA module with a 5mm diameter rod and quasi-continuous-wave (QCW)
pumping of the laser diodes are shown below. The gain of Er:YAG is much lower than typical Nd:YAG
systems. The best output coupler reflectivity to maximize output power was 95% in a short cavity of
280mm length with a flat high reflector. Fluorescence imaging of the 2.94um emission showed
good uniformity of absorbed diode light (see Figure 1.) Imaging the output coupler, a uniform beam
profile was observed (see Figure 2.)

Figure 3 shows output energies per pulse obtained during short cavity testing for various pulse
widths. With the same duty cycle, the module was tested at 500μs, 1ms, and 1.5ms. Efficiencies of
pump energy to output energy of 19%, 22%, and 18% were obtained for 500μs, 1ms, and 1.5ms
respectively. The energy level dynamics of the Er:YAG system is complex. Due to thermally driven
effects, the tail end of the optical pulse fell off for pulse widths longer than 1ms. This explains the
reduction in efficiency for 1.5ms pulses. At 15Hz and 1ms, a maximum average output power of
70W was obtained. The maximum output energies per pulse obtained for 500μs, 1ms, and 1.5ms
were 2J, 4.67J, and 5.66J, respectively.

Due to the high quantum defect in Er:YAG, thermal lensing is an important consideration when
building an Er:YAG laser. The power of the thermal lens in this module was measured to be 0.012
diopters per watt of average pump power plus a baseline of 0.173 diopters above the threshold.
The successful testing of a new Er:YAG, 5mm diameter side pumped rod laser module was
performed, with output pulse energies of up to 5.5J and average powers exceeding 50W achieved.
This module is based on the CEO’s industry-proven REA laser module series designs used for the past
several decades as oscillators and amplifiers in a variety of DPSS laser applications. These
modules are typically rated for lifetimes greater than 10 billion pulses, which exceeds the projected
lifetime of medical equipment in many environments.

Approved for Public Release: NG25-0073. © 2025 Cutting Edge Optronics, Inc.