In this paper, we summarize our previous relevant works and demonstrate various approaches to overcome the common drawbacks of applying Raman probes for many applications. A handheld fiber-optic Raman probe with an autofocus unit was presented to overcome the problem arising from using fixed-focus lenses, by using a liquid lens as the objective lens, which allows dynamical adjustment of the focal length of the probe. An implementation of a computer vision-based positional tracking to co-register the regular Raman spectroscopic measurements with the spatial location enables fast recording of a Raman image from a large tissue sample by combining positional tracking of the laser spot through brightfield images. The visualization of the Raman image has been extended to augmented and mixed reality and combined with a 3D reconstruction method and projector-based visualization to offer an intuitive and easily understandable way of presenting the Raman image. All these advances are substantial and highly beneficial to further drive the clinical translation of Raman spectroscopy as potential image-guided instrumentation.

The steady progress in medical diagnosis and treatment of diseases largely hinges on the steady development and improvement of modern imaging modalities.Raman spectroscopy has attracted increasing attention for clinical applications as it is label-free,non-invasive,and delivers molecular fingerprinting information of a sample.In combination with fiber optic probes,it also allows easy access to different body parts of a patient.However,image acquisition with fiber optic probes is currently not possible.Here,we introduce a fiber optic probe-based Raman imaging system for the real-time molecular virtual reality data visualization of chemical boundaries on a computer screen and the physical world.The approach is developed around a computer vision-based positional tracking system in conjunction with photometric stereo and augmented and mixed chemical reality,enabling molecular imaging and direct visualization of molecular boundaries of three-dimensional surfaces.The proposed approach achieves a spatial resolution of 0.5 mm in the transverse plane and a topology resolution of 0.6 mm,with a spectral sampling frequency of 10 Hz,and can be used to image large tissue areas in a few minutes,making it highly suitable for clinical tissue-boundary demarcation.A variety of applications on biological samples,i.e.,distribution of pharmaceutical compounds,brain-tumor phantom,and various types of sarcoma have been characterized,showing that the system enables rapid and intuitive assessment of molecular boundaries.

Current implementations of fiber-optic Raman spectroscopy probes are frequently based on non-contact probes with a fixed focus and thus and have to precisely maintain the probe-to-sample distance to ensure a sufficient signal collection. We propose and experimentally demonstrate a novel hand-held fiber-optic Raman probe design, which is based on a liquid lens autofocusing unit, combined with a distance sensor and an in-house developed algorithm to precisely determine the probe-to-sample distance. The reported probe significantly improves the signal stability even for hand-held operation, while reducing distance-dependent artifacts for the acquisition of Raman spectra and can improve the acquisition of Raman spectra in a variety of applications.

Raman spectroscopy using fiber optic probe combines non‐contacted and label‐free molecular fingerprinting with high mechanical flexibility for biomedical, clinical and industrial applications. Inherently, fiber optic Raman probes provide information from a single point only, and the acquisition of images is not straightforward. For many applications, it is highly crucial to determine the molecular distribution and provide imaging information of the sample. Here, we propose an approach for Raman imaging using a handheld fiber optic probe, which is built around computer vision–based assessment of positional information and simultaneous acquisition of spectroscopic information. By combining this implementation with real‐time data processing and analysis, it is possible to create not only fiber‐based Raman imaging but also an augmented chemical reality image of the molecular distribution of the sample surface in real‐time. We experimentally demonstrated that using our approach, it is possible to determine and to distinguish borders of different bimolecular compounds in a short time. Because the method can be transferred to other optical probes and other spectroscopic techniques, it is expected that the implementation will have a large impact for clinical, biomedical and industrial applications.

A compact and low cost optical fiber sensor by introducing higher order modes interference with fiber twisting based on single-mode-multimode-single-mode structure is proposed and demonstrated for simultaneous measurement of strain and temperature. The sensor is fabricated by heating and twisting a section of multimode fiber (MMF), which is spliced between two single-mode fibers. By adjusting the heating temperature and rotate speed during fabrication, the twisted region is introduced in MMF, which is able to couple more power of light into the cladding and introduce higher order modes in modal interferences. With this method, strain sensitivity of -7 and -2.19 pm/mu epsilon as well as temperature sensitivity of 17.33 and 13 pm/degrees C are obtained. By spatial frequency demodulation method, measurement resolution reaches +/- 2.14 mu epsilon and +/- 0.89 degrees C, which has great potential in dual-parameters measurement of temperature and strain with high resolution.

A low-cost way of achieving a high sensitivity optical fiber strain sensor by introducing higher-order interference modes using a torsional multimode fiber (MMF) instead of normal MMF based on single-mode–multimode–single-mode (SMS) structure is proposed and the coupling mechanism of twist fiber is investigated theoretically. The sensor is fabricated by simple process of heating and twisting a small region of MMF. According to this method, the shift of multimode interference spectrum caused by an axial strain will be greatly magnified. Different strain sensitivities can be easily realized by controlling the torsional number of circles. The experimental results indicated a high strain sensitivity of 42.5 pm/με at most.

In this paper, we demonstrate a switchable single-longitudinal-mode (SLM) dual-wavelength fiber laser in 2-μm region based on a core-offset structure and carbon nanotube (CNT). The switchability of the fiber laser is based on a core-offset structure which acts as a tunable filter, so that the laser can work in stable dual-wavelength operation or switch between two wavelengths by adjusting the curvature of the core-offset structure. 3.68 nm (1919.44–1923.12 nm) and 6.32 nm (1890.64–1896.96 nm) tuning range can be obtained by tuning FBGs, respectively. The wavelength shift is less than 0.08 nm, and the power variation is smaller than 0.5 and 1 dB at 1923 and 1897 nm, respectively. The SLM oscillation is guaranteed by the CNT, which works as the loss factor to realize SLM oscillation. Absorption of the CNT increases the lasing threshold of the laser, therefore only the stronger mode can get lasing and SLM emission can be obtained. The proposed fiber laser offers a convenient and low-cost design for switchable dual-wavelength fiber laser in 2-μm region which has potential application in fields of gas sensing, lidar, and so on.

A switchable and tunable dual-wavelength single-longitudinal-mode (SLM) fiber laser in a 2-μm region based on saturable absorber and self-injection locking is proposed and experimentally demonstrated. The laser topology is based on the parallel connection of fiber Bragg gratings (FBGs) using a coupler to realize switchability and tunability by adjusting the cavity losses and the center wavelengths of FBGs, respectively. The saturable absorber and the self-injection locking ensure the stable operation of the laser at SLM. Dual-wavelength with the power-instability of ~0.7 dB, the wavelength drift of ±0.08 nm, and a tuning range of 6.7 and 2.7 nm is obtained. Stable SLM operation with linewidths of <;9.1 MHz analyzed by the self-homodyne method is obtained. The proposed configuration has ingenious and compact structure and reliable performance, and will have promising applications in the fields of multiparameter detection in gas sensing or new wavelength-division-multiplexing (WDM) communication systems.

A 2μm novel dual-wavelength single-longitudinal-mode (SLM) fiber laser based on saturable absorber and self-injection locking which can ensure SLM operating stable is reported. The proposed configuration has ingenious and compact structure, and reliable performance.

A novel acoustic sensor based on a polypropylene/poly (ethylene terephthalate) (PP/PET) diaphragm is demonstrated. The Michelson interferometer is formed by two beams of light that are reflected into optical fiber collimators by both sides of the PP/PET film. The deformation of diaphragm caused by acoustic signal will be magnified twice in the optical path of proposed sensor. The sensitivity of our proposed sensor is more than -128 dB re 1 rad/μ Pa in the frequency range of 90-4000 Hz, and a signal-to-noise ratio of ~ 42dB is achieved at 600 Hz. Due to its superiorities of low cost, small size, high sensitivity, and easy fabrication, the proposed sensor exhibits a potential for low-frequency acoustic sensing and healthy monitoring.

We demonstrate a switchable, tunable and power-controllable dual-wavelength fiber laser in 2-μm region based on parallel cavities using a 3 × 3 coupler. The laser topology is based on the parallel connection of fiber Bragg gratings (FBGs) using 3 × 3 coupler which act as two individual cavities, so that the dual wavelengths are tunable and switchable by adjusting the center wavelengths of FBGs and the cavity losses, respectively. With suitable cavity losses and input pumping power, we can obtain a 2-μm switchable single- or dual-wavelength fiber laser. The proposed configuration has very good application prospects in the fields of atmospheric transmission, gas sensing, lidar and new wavelength-division-multiplexed fiber communication systems.

We demonstrated a 2µm switchable, tunable and power-controllable dual-wavelength fiber laser by adjusting the center wavelengths of FBGs and the cavity losses, respectively. The topology is based on the parallel connection of FBGs using 3×3coupler.

We demonstrated a 2-μm switchable dual-wavelength fiber laser with cascaded filter structure based on dual-channel Mach–Zehnder interferometer and spatial mode beating effect. Few-mode fiber-embedded Sagnac ring configuration and a Mach–Zehnder interferometer are cascaded to form a multiwavelength filter for our previous 2-μm fiber laser. By adopting suitable fiber length and adjusting the polarization controller, we obtained a 2-μm dual-wavelength fiber laser with switchable wavelength interval. Experimental results revealed that the proposed laser shows higher quality and better stability compared with our previous work and it has potential applications in the fields of atmospheric propagation and microwave photonics.

目的探讨产科住院患者对护理服务的需求,为产科优质护理服务的内涵提供依据。方法采用自设问卷的方法,选择2010年4-5月在我科住院的96例初产妇作为研究对象进行问卷调查,自然分娩组48例,剖宫产组48例。结果不同分娩方式产妇对基础护理及生活护理的需求不同,但对健康教育的需求都很强。12.50%自然分娩及50.00%剖宫产的产妇需要护士协助生活护理;43.75%自然分娩及54.17%剖宫产产妇需要护士实施基础护理;58.33%的产妇需要提供一对一的导乐陪伴分娩;60.42%自然分娩及64.58%剖宫产产妇需要提供电话随访,必要时上门随访;81.25%自然分娩及83.33%剖宫产产妇需要母乳喂养指导;83.33%自然分娩及81.25%剖宫产产妇需要护士经常巡视病房需要时随叫随到;85.42%自然分娩及87.50%剖宫产产妇关注新生儿护理知识;91.67%的产妇关注产后健康教育指导及产褥期卫生知识。结论做好产妇基础护理,协助剖宫产产妇生活护理以及开展多种形式的健康教育,才能更好体现"以人为中心"的产科优质护理服务。