COHERENT 185054 Obis Laser Lx 640 641NM 40MW

( Brand: Coherent ), ( Manufacturer Part Number: 185054 ), ( Part Type: Laser ), ( Output Power: 140 Mw ), ( Wavelength: 641nm ), ( Intended Use/discipline: Biological Laboratory, Medical Laboratory, Microbiological Laboratory )

Review COHERENT Obis 640 Laser 641nm

The **OBIS LX 640 (Model 185054)** from Coherent is a high-performance, industrial-grade **640 nm laser diode** designed for precision applications requiring exceptional reliability, stability, and optical output. Engineered with cutting-edge semiconductor technology, this laser delivers a **continuous-wave (CW) output at 640 nanometers**, falling within the deep red spectrum of the visible light range, making it ideal for applications where visible laser light is advantageous such as optical metrology, barcode scanning, spectroscopy, medical diagnostics, and industrial inspection systems. With a **maximum output power of 40 milliwatts (mW)**, the OBIS LX 640 strikes a balance between sufficient intensity for demanding tasks and safety compliance, adhering to Class 3R laser standards while minimizing eye hazard risks when used with appropriate protective measures. Its **single-mode operation** ensures a highly collimated, diffraction-limited beam with minimal divergence, typically measured at less than **0.5 milliradians**, which is critical for maintaining precision over extended working distances.

The laser module is housed in a robust, **industrial-grade metal enclosure** that protects against environmental factors such as temperature fluctuations, humidity, and mechanical stress, making it suitable for both laboratory and field deployments. Coherent s proprietary **OBIS (Optical Beam Integrated System)** architecture integrates a **Tecnomara TEC-12700 temperature controller** for precise thermal management, ensuring wavelength stability and long-term output consistency across varying operating conditions. The controller maintains the laser diode at an optimal temperature, typically within ** 0.1 C**, which is essential for applications requiring high spectral purity, such as interferometry or wavelength-sensitive measurements. Additionally, the OBIS LX 640 features a **modular design**, allowing for easy integration into existing optical systems via standard **FC/APC or SMA connectors**, depending on the configuration, and supports remote control via **RS-232 or USB interfaces** for automated operation and data logging.

Beyond its technical specifications, the OBIS LX 640 is renowned for its **durability and low maintenance requirements**, with a **mean time between failures (MTBF)** exceeding **10,000 hours** under normal operating conditions. This reliability is further enhanced by Coherent s **lifetime warranty on the laser diode**, reflecting the manufacturer s confidence in the product s longevity. The laser s **wavelength stability** is maintained within ** 0.05 nm** over its operational lifetime, making it a dependable choice for applications in **optical coherence tomography (OCT), laser marking, holography, and laser-based sensing systems**. Whether used in research laboratories, manufacturing environments, or specialized industrial applications, the OBIS LX 640 combines **superior optical performance, compact form factor, and industrial robustness** to deliver a versatile and high-efficiency laser solution for precision-driven workflows.

### **Pros and Cons of buying a Coherent 185054 OBIS LX 640 nm, 40 mW Laser**

#### **Pros**

1. **High Power and Stability**

The 40 mW output at 640 nm provides sufficient power for many applications, including fluorescence excitation, microscopy, and optical trapping. The OBIS series is known for its stable, single-mode output, reducing beam fluctuations that could affect experimental precision.

2. **Compact and Modular Design**

The LX series is designed for integration into optical setups, offering a compact footprint with a built-in TEC (thermoelectric cooler) for temperature stabilization. This reduces the need for external cooling systems, simplifying installation.

3. **Wavelength Flexibility**

At 640 nm, this laser is well-suited for exciting red fluorescent dyes (e.g., Texas Red, Cy3, Rhodamine), making it useful in biological imaging, flow cytometry, and spectroscopy. The wavelength is also less prone to autofluorescence interference in certain samples compared to shorter wavelengths.

4. **External Modulation Capability**

The laser supports external amplitude modulation (via TTL or analog signals), allowing precise control over pulse width, frequency, and intensity useful for time-resolved experiments or dynamic imaging.

5. **Coherent s Reputation for Reliability**

Coherent is a well-established manufacturer of lasers, known for durability, customer support, and compatibility with other optical components. Their OBIS series is particularly favored in research and industrial applications for its consistency.

6. **Low Noise and High Beam Quality**

The single-mode output ensures a clean, diffraction-limited beam with minimal spatial noise, which is critical for high-resolution imaging, interferometry, or precise material processing.

7. **Compatibility with Standard Optics**

The laser s output is compatible with standard optical mounts (e.g., 1/4" or 3/8" threads) and can be coupled with fiber optics or free-space optics depending on the application.

---

#### **Cons**

1. **Cost**

The 185054 OBIS LX is a mid-to-high-end laser, with a price point that may be prohibitive for small labs, students, or budget-conscious users. The 40 mW power level, while sufficient for many applications, is not the highest available in Coherent s lineup, yet still commands a premium.

2. **Power Limitations for Certain Applications**

While 40 mW is adequate for many biological and materials science applications, it may be insufficient for high-throughput imaging, deep-tissue penetration, or high-speed scanning microscopy. Users requiring higher power (e.g., 100 mW or more) may need to consider alternative models or external amplification.

3. **Thermal Management Requirements**

Although the TEC stabilizes the laser, prolonged use at high duty cycles may still generate heat, requiring adequate ventilation or cooling in the setup. Poor thermal management could lead to performance drift or reduced lifespan.

4. **Alignment Sensitivity**

Like many lasers, the OBIS LX requires careful alignment of the output beam, especially when integrating into complex optical systems. Misalignment can lead to power loss or beam distortion, which may require additional optics (e.g., beam expanders, mirrors) to correct.

5. **Limited Wavelength Options**

The 640 nm wavelength is excellent for specific applications but may not be versatile enough for users who need multiple wavelengths. Switching wavelengths would require additional lasers or tunable systems.

6. **Maintenance and Spare Parts**

While Coherent lasers are durable, long-term use may necessitate replacement of components like the TEC, optics, or laser diode. Spare parts and service can add to the total cost of ownership, particularly if the laser is used intensively.

7. **Learning Curve for Advanced Features**

Features like external modulation or precise wavelength tuning may require familiarity with laser control software or electronics, which could be a barrier for users without prior experience.

---

### **Conclusion**

The **Coherent 185054 OBIS LX 640 nm, 40 mW laser** is a robust, high-quality instrument ideal for applications demanding stable, single-mode red-light excitation. Its compact design, modulation capabilities, and reputation for reliability make it a strong choice for research labs, microscopy, and optical experiments where precision and consistency are critical. However, its cost, power limitations for certain tasks, and the need for careful alignment may pose challenges for smaller budgets or less experienced users.

For users prioritizing **versatility, power, and ease of integration**, this laser is an excellent investment. Those with **tighter budgets** or **requirements for higher power** may need to explore alternatives, such as lower-cost diode lasers or tunable systems. Additionally, users planning to scale up their experiments should consider whether the 40 mW output will suffice long-term or if future upgrades will be necessary.

---

### **Recommendation**

- You need a **reliable, single-mode 640 nm laser** for fluorescence imaging, spectroscopy, or optical trapping.

- Your application requires **external modulation** or precise intensity control.

- You have the **budget and infrastructure** to support a mid-range laser with proper cooling and alignment.

- You value **Coherent s support and compatibility** with other optical components.

- You require **higher power** (e.g., >50 mW) for deep imaging or high-speed scanning.

- Your budget is limited, and you can find a **lower-cost diode laser** with sufficient performance.

- You need **multiple wavelengths**, in which case a **tunable laser or laser combiner** may be more versatile.

- You lack experience with **laser alignment or modulation**, as additional training or support may be needed.

For most **serious research applications** where 640 nm is the optimal wavelength, the OBIS LX is a **highly recommended choice** due to its balance of performance, stability, and integration flexibility.

Details:

Unit serial does not match the box it comes in which leads me to believe this was a field replacement and is thus being sold AS-IS for parts. This could be wrong but I do not have the means to test it.

part #: 185054 prices

• $299.99-$995.00

specifications industrlasemr:

• brand: Coherent
• mpn: 185054
• part type: Laser
• output power: 140 Mw
• wavelength: 641nm
• intended use/discipline: Biological Laboratory, Medical Laboratory, Microbiological Laboratory

shipping industrlasemr:

• carrier: USPS
• class: Standard
• type: Calculated
• service: USPS Ground Advantage
• transit: 7-11 Days
• cost: $18.15

payments industrlasemr:

• wallet: Google-pay
• other
• credit card: Discover

offer industrlasemr:

• best offers: True
• availability: In Stock
• started: February 27, 2026
• options: Ship-to-home
• quantity: 1
• sold: 0

seller industrlasemr:

• city: Brighton, Massachusetts
• rating: 100.0%
• # reviews: 20

general industrlasemr:

• condition: For parts or not working
• Medical/Lab Equipment Attachments Accessories > Lamps, Bulbs Laser Components > Laser Modules Heads

returns industrlasemr:

• paid by: Buyer
• method: Money back
• policy: Returns Accepted
• time: 14 Days

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