Micro objective lens with NA 065 for the bluelight small-form-factor optical pickup head

Abstract

We present a novel technique, intrinsic Raman spectroscopy (IRS), to correct turbidity-induced Raman spectral distortions, resulting in the intrinsic Raman spectrum that would be observed in the absence of scattering and absorption. We develop an expression relating the observed and intrinsic Raman spectra through diffuse reflectance using the photon migration depiction of light transport. Numerical simulations are employed to validate the theoretical results and study the dependence of this expression on sample size and elastic scattering anisotropy.

Prism-type holographic optical element design and verification for the blue-light small-form-factor optical pickup head

“…It adopts a finiteconjugate objective lens of NA 0.65 and a blue laser of wavelength 405 nm. The specifications of the objective lens and system spacing are the same as those described in the previous report [12]. The laser is edge-emitting in the form of a bare chip bonded on a submount and placed upon a substrate.…”

“…Due to integration of multiple functions in one element, the proposed SFF-OPH could be effectively simplified. Table 1 shows the comparison of the optical component number between the previous [9,12] and proposed designs. The diffraction surface can be designed by using the reflective binary surface of optical ray-tracing software.…”

“…Because the grating pitch is larger than the working wavelength, the scalar diffraction theory is applicable to the diffraction efficiency calculation formulated in Eqs. (11) and (12) for the zeroth and first orders, respectively. Figure 4 depicts the efficiencies of the first order, the zeroth order, and the multiplication of two orders corresponding to the grating depth change.…”

“…Shih et al also proposed a system assembly method for precisely aligning components by using virtual images of the photodetector (PD) and laser from the HOE diffraction. Based on the design configuration, there have been a series of studies presented to fulfill and strengthen its feasibility, such as the micro blue-light objective lens with the numerical aperture (NA) of 0.65 [12], the dual-stage seesaw-swivel actuator [13][14][15][16], the astigmatic reflector [17], and the fabrication using microelectromechanical systems (MEMS) technologies [18,19]. The servo characteristics of the design have been successfully verified by Hou et al [20][21][22] for the red-light system and by Lin et al [23] for the blue-light system, respectively.…”

Enhancement of Optical Adaptive Sensing by Using a Dual-Stage Seesaw-Swivel Actuator with a Tunable Vibration Absorber

“…In such a high speed positioning servo system, the head/disk spacing variation must be maintained as small as possible during disk operations. While attempting to reduce the size of optical heads, several works have scaled down all components of a conventional unit [1,2] and simplified the optical configuration, and micro optical elements, such as lenses and prisms. Other approaches integrate an optical module with a seesaw swivel actuator [3,4].…”